A New Genus And Species Of "goneplacid-Like" Brachyuran Crab (Crustacea Use Of The Family Pseudorhombilidae Alcock, 1900

11 Pages·1998·4.1 MB·

by  M E Hendrickx

PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON
lll(3):634-644. 1998.
A new genus and species of "goneplacid-like" brachyuran crab
(Crustacea: Decapoda) from the Gulf of California, Mexico,
and a proposal for the use of the family
Pseudorhombilidae Alcock, 1900
Michel E. Hendrickx
Institute de Ciencias del Mar y Limnologia, Estacion Mazatlan, UNAM. P.O. Box 811,
Mazatlan, Sinaloa 82000, Mexico
—
Abstract. A new genus and species of crab, Bathyrhombila furcata, are
described from localities in the Gulf of California, western coast of Mexico.
The new genus is close to Pseudorhombila H. Milne Edwards and belongs to
a group of three genera tentatively assigned to the subfamily Pseudorhombi-
linae Alcock, 1900 by Guinot in 1969. The affinity of Bathyrhombila, new
genus, with other genera of "Goneplacidae" {Euphrosynoplax Guinot, Pseu-
dorhombila H. Milne Edwards, Nanoplax Guinot, Oediplax Rathbun, and Cha-
cellus Guinot) is discussed, noting that they all represent primitive transitional
forms between the cyclometopous and the catometopous abdomen-sternum or-
ganization, and a similar "xanthoid-goneplacid" facies. On the basis of these
affinities, it is proposed that these six genera be included into the family Pseu-
dorhombilidae Alcock, within the Heterotremata Guinot, 1977.
—
Resumen. Se describe un nuevo genero y una nueva especie de cangrejo,
Bathyrhombila furcata, recolectado en localidades de el golfo de California,
costa oeste de Mexico. El nuevo genero se parece a Pseudorhombila H. Milne
Edwards y pertenece a un grupo de tres generos tentativamente asignados a la
subfamilia Pseudorhombilidae Alcock, 1900 por Guinot en 1969. Se discute la
afinidad de Bathyrhombila, nuevo genero, con otros genero de "Goneplacidae"
{Euphrosynoplax Guinot, Pseudorhombila H. Milne-Edwards, Nanoplax Guin-
ot, Oediplax Rathbun, y Chacellus Guinot), seiialando que todos ellos repre-
sentan formas primitivas de transicion entre la organizacion abdomen-estemon
cyclometopes y catametopes, y una apariencia similar de tipo "xanthoideo-
goneplacideo". En base a estas afinidades, se propone que estos seis generos
scan incluidos en la familia Pseudorhombilidae Alcock, dentro del grupo de
los Heterotremata Guinot, 1977.
Two common and widely distributed Xanthoidea proposed by Guinot (1978) em-
families ofbrachyuran crabs, the Xanthidae phasized the sternal position of female
and Goneplacidae (sensu Balss 1957) have openings ("stemitremes") coupled with the
long been recognized as containing hetero- coxal or coxo-stemal position of male gen-
geneous groups ofgenera (see Guinot 1970, ital openings, thus relating the Xanthoidea
1977, 1978; Serene 1984; Williams 1984; with the heterotremateous arrangement
&
Martin Abele 1986). In the last twenty (Heterotremata, as definedby Guinot 1977).
years, the organization of the Xanthidae Guinot (1978) insisted on the fact that
sensu Balss has been subject to many among the Xanthoidea, two groups of fam-
changes. The concept of a superfamily ilies should be considered: one with male
VOLUME 111, NUMBER 3 635
opening coxal, and another in which the entre Cyclometopes et Catometopes [an or-
male opening progressively migrates to a ganization close to the cyclometopous or-
coxo-sternal position. In the later group, the ganization and probably belonging to the
evolutionary process is associated with a crabs linking the cyclometopous to the ca-
modification of the facies, which becomes tametopous]." A second species of Chacel-
goneplacid-like (Guinot 1978:266). Guinot lus was added by Hendrickx (1989a) who,
(1978) also suggested that when all genera despite of a "rather xanthoid facies," in-
ofGoneplacidae sensu Balss will have been cluded it in the Goneplacidae with a "prim-
reviewed, new families might be added to itive catometopous organization." Another
the second, goneplacid-like group of Xan- genus, Euphrosynoplax Guinot, 1969b was
thoidea (i.e., those genera with a coxo-ster- also described by Guinot (1969b:720), to
nal male openings). accommodate an undescribed species of
A
group of goneplacid-like brachyuran crab from Florida: E. clausa Guinot, 1969b.
crabs presently included in the Goneplaci- Again, Guinot (1969b) emphasized the
dae has long been recognized as represent- primitive catometopous stage ofthis genus,
ing an intermediate step towards the trans- relatively close to the cyclometopous ar-
formation of the cyclometopous (heterotre- rangement. A second species of Euphrosy-
matous) abdomen-sternum arrangement noplax was recently described by Vazquez-
(male genital opening coxal; abdominal so- Bader & Gracia (1991) from the Gulf of
mites 1-2 covering entirely the space be- Mexico. Although these authors did not
tween the coxa of P5; stemite plate 8 en-
clearly illustrate sternite eight, they refer to
tirely covered by these abdominal somites a (what appears as a primitive) catometo-
and not visible ventrally) into a catometo- pous organization of their species, E. cam-
pous arrangement (male opening sternal;
pechiensis, with a ". male opening coxal
stemite plates 7 and 8 widened, ventrally . .
[and] a small portion of stemite 8 not cov-
united and visible ventrally; abdominal seg-
ered by the second abdominal somite."
ments 1—2 reduced, clearly separated from
The present paper deals with a new spe-
coxa of P5) (Guinot 1969a, 1978, 1979).
cies ofcrab that present morphological sim-
For Guinot (1969b, 1970) this group of
ilarities with those in the above cited gen-
genera represents an evolutionary step to-
wards the more advanced catometopous era. It is herein considered that this new
species requires a new genus. Furthermore,
(thoracotrematous) organization in which
the use of the family Pseudorhombilidae
the sternum occupies an increasingly wider
area between the basal abdominal somites Alcock, 1900, is proposed for a group of
and the coxa of P5, and the male opening six genera with a "xanthoid-goneplacid"
moves progressively towards a sternal po- facies representing primitive transitional
sition. Guinot (1970: 1076, 1080) suggested forms between the cyclometopous and the
that several of these genera (i.e., Pseudo- catometopous abdomen-sternum organiza-
rhombila H. Milne Edwards, 1837, Oedi- tion.
plax Rathbun, 1893, and possiblyNanoplax Abbreviations used in this paperare: CW,
Guinot, 1967) could be integrated in the carapace width; CL, carapace length; P2 to
subfamily Pseudorhombilidae Alcock, 1900 P5, pereiopods; PU and P12, male first and
pro parte. second pleopods (gonopods), respectively;
Guinot (1969b: 721) also described the SEM, Scanning Electron Microscope;
genus Chacellus Guinot, 1969b, monotypic EMU, Estacion Mazatlan UNAM, inverte-
at that time, which she considered "... [a brate reference collection; SIO, SCRIPPS
genus with] une organisation tres proche de Institution of Oceanography, invertebrates
rorganisation cyclometopienne et fait sans collection. La Jolla, California, U.S.A.;
doute partie des Crabes formant le passage LACM, Los Angeles County Museum of
636 PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON
Natural History, Los Angeles, California, curved, gap between fingers reduced. A
U.S.A. very conspicuous, strong pterygostomian
Drawings were made with a camera lu- ridge in front of cheliped articulation.
cida (Fig. 2). Holotype was photographed Walking legs slender, long, flattened. Ster-
using a Kodak TMAX 100 ASA black and nummoderately wide, narrowing in frontof
white film (Fig. 1), and SEM microphoto- PI. Abdomen narrow in its base; segment
graphs ofmale gonopods were obtained us- 2 not overlapping coxa of P5. Abdominal
ing the classical technique of acetone de- segments 3-5 incompletely fused; suture 3-
hydrated, gold-palladium coated gonopods 4 distinguishable, a remaining notch on
extracted from type material (Fig. 3). both extremities; suture 4-5 obsolete, a re-
maining notch on both extremities. A small
Bathyrhombila, new genus portion of sternite 8 visible, close to artic-
— ular condyle ofP5, not in contact with ster-
A
Diagnosis. Carapace 1.4 to 1.5 broader nite plate 7. shallow depresion in front
than long, anteriorly convex, slightly con- ofthe abdominal telson. Male genital open-
vex and narrowerposteriorly; general shape ing coxal and gonopod 1 free. Pll long,
"xanthoid". Antero-lateral margin arched, slender, with slightly curved apex; stiffsub-
with 4 teeth, excluding the outer orbital terminal spines, with stout and long lateral
tooth which is well-defined and slightly (apical) process and shorter, hook-like api-
projecting; second and outer orbital teeth cal process. P12 s—hort, sigmoid.
fused, forming an almost straight slightly Type species. Bathyrhombila furcata,
projecting margin; length of this margin al- new species, by original designation and
most half the frontal width. Postero-lateral monotypy. —
border converging posteriorly. Regions rel- Ethymology. The name of the genus is
atively well marked. Frontnarrow, less than a combination of rhombila and bathys, to
Vs maximum width of carapace, slightly indicate affinities with the genus Pseudo-
projecting forwards, with a shallow median rhombila H. Milne Edwards and the fact
depression, margin sinuous, with a well- that most specimens were collected in the
marked notch between the external comer bathybenthic region.
and the inner orbital tooth. Orbits reduced
in size; eyes relatively small. Upper orbital Bathyrhombilafurcata, new species
margin slightly concave, with 2 distinct su- Figs 1-3
tures; lower orbital margin with 2 strong —
teeth, inner one acute, outer one rounded. Material examined. Holotype, male
Antennal flagellum long, entering orbit; ba- (CW 24.6 mm; CL 17.5 mm), 05 Jul 1965,
sal article ofantenna relatively long, slight- station SIO 65-257, La Paz Bay (24°19'N,
ly oblique, in contact with front; a small 110°26'W), Baja California, Mexico, otter
m
apophyse intercalated between basal article trawl, 55-80 (coll. W. Baldwin) (SIO C-
and epistome (pterygostomian upper bor- 2116).
der); palp folding horizontaly. Interanten- Paratypes: male (CW 20.3 mm; CL 14.45
nular septumbroadly triangular. Thirdmax- mm), 18 Jan 1968, station MV68-I-59, Gulf
illiped with merus about 0.5 times length of of California, north of Angel de La Guarda
ischium, antero-external angle slightly pro- Island (29°41'N, 113°56'W), Baja Califor-
duced; palp articulating at inner distal angle nia, Mexico, 566-644 m, otter trawl, RA'^
of merus. Chelipeds large and robust, not T. Washington (coll. C. Hubbs) (SIO C-
markedly unequal in large males, subequal 5669A). Male, slightly damaged (CW 22.8
in females; carpus with a blunt, moderately mm; CL 16.35 nrni), 18 Jan 1968, station
large spine at inner angle; pincers very MV68-I-59, Gulf of California, north of
large, fingers flattened, pointed, tips re- Angel de La Guarda Island (29°41'N,
VOLUME 111, NUMBER 3 637
113°56'W), Baja California, Mexico, 566- long (length of major claw about equal to
644 m, otter trawl, RA'^ T. Washington CW), right claw being slightly higher
(coll. C. Hubbs) (LACM-68-464.1, ex-SIO (right/left claw maximum height ratio 1.09
C-5669). to 1.12). Merus with granules on anterior
Non-paratypes: 1 soft shell male (cw and posterior sides, adorsal row ofgranules
25.95 mm; CL 17.95 mm), 1 damaged soft- and a blunt superior subterminal angle, pro-
shell ovigerous female (CW ca. 17.9 mm; duced in a low tubercle. Carpus strong,
CL ca. 13.0 mm), 18 Jan 1968, station obliquely subquadrate in dorsal view, sur-
MV68-I-59, Gulf of Cahfomia, north of face slightly irregular dorsally; clusters of
Angel de La Guarda Island (29°4rN, granules arranged in rugae (well defined in
113°56'W), Baja California, Mexico, 566- the holotype) on outer slope; a blunt, mod-
644 m, otter trawl, RA'^ T. Washington erately large spine at inner angle; a well-
(coll. C. Hubbs)—(SIO-5669C). defined sulcus parallel to distal border. Ma-
Description. Carapace wide (CW/CL nus inflated, smooth (microscopicallypunc-
mm
ratio 1.40-1.46). Front narrow (7.05 tated). Fingers long, flattened, pointed,
wide in holotype), sinuous; fronto-orbital strongly incurving and with recurved tips,
mm
width (13.4 in holotype) about halfthe gap between fingers reduced; length ofdac-
carapace width. Carapace anteriorly convex tylus of major claw ca. 0.4 times length of
and mostly covered with small flattened claw; dorsal margin of dactylus of major
granules, without setae; granules more nu- claw almost straight, that of major claw
merous and rounded close to edges and on only slightly curved. Cutting edge of dac-
antero-lateral teeth. Antero-lateral margin tylus of both claws sharp, that of major
with five teeth (including the outerorbital claw with a strong, projecting subrectan-
tooth), the posterior three large to medium- gular proximal tooth, followed by a series
sized, conical; second teeth reduced, fused of irregular, smaller teeth; cutting edge of
with the outerorbital tooth and forming an polex with a series of irregular teeth; cut-
almost straight, little projecting margin; ting edges of smaller claw with reduced
outerorbital tooth little produced, distinct. teeth.
Fifth tooth smaller than the preceeding two; Pereiopods 2-5 long, slender, flattened;
fourth teeth acute, pointing upward; third merus covered with dense granules on low-
teeth wider that fourth and fifth, its sides at er and upper margin, sides almost smooth;
a right angle, flattened compared to fourth. carpus and propodus partly covered with
Orbital lobe well-marked; upper orbital granules on upper margin; a low, longitu-
margin somewhat irregular, with small dinal granulated crest on upper margin of
rounded granules and two conspicuous su- carpus; dactylus about same length as prop-
tures (median and lateral); lower orbital odus, with longitudinal rows of setae, tip
margin with granulated inner tooth and out- short, corneous. Pereiopods 2-4 subequal
er lobe, both granulated. Outer orbital tooth in length (P2 = 1.66 times CW; P3 = 1.69
well-defined, little projecting. Pterygosto- times CW; P4 = 1.63 times CW), fifth pe-
mian and subhepatic regions granulated. reiopod notably shorter (1.39 times CW).
A
Pterygostomian ridge coarsely granulated. small portion of stemite eight of male
Distal border of merus of third maxilli- abdomen visible between second and third
ped sinuous, with a marked median concav- abdominal somites; first and third somites
ity; antero-extemal angle little produced; slightly wider than second, second andthird
merus coarsely granulated; ischium with of about the same length and with subacute
more flattened granules, its distal border lateral margins; sixth somite wider than
produced internally in a lobe; palp coarse. long, sides concave, narrowermedially, dis-
Cheliped very strong, long (lengthofma- tal and proximal margin equal; seventh so-
jor cheliped ca. 1.75 CW); claw heavy and mite (telson) as long as sixth, posteriorly
638 PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON
Fig. 1. Holotype, male, CW 24.6 mm, CL 17.5 mm, dorsal view. La Paz Bay, BajaCalifornia, Mexico (SIO
C-2116).
rounded. First somite and lateral portion of of the smallest whereas it is 1.11 in the ho-
second coarsely granulated; other somites lotype. The soft-shell male is also the larg-
with fewer flattened granules or almost est male available but due to the lack of
smooth. calcification this specimen has not been
Female gonopores longitudinally oval; used as holotype. The only available female
opening vertical. also features a soft-shell, and althoughbasic
First pleopod of male long, slender, characteristics match the description of the
bending and slightly curved distally. Two species, it was not designated as type ma-
rows ofsmall spines on the shaft; two series terial either. The bathymetric range of B.
of 3 and 5 much longer distal spines on furcata is rather wide; the holotype was
each side of the fold, close to the apex; a taken in trawl between 55 and 80 m, while
strong, spine-like subterminal process, and the rest of the material was obtained in a
a terminal, hook-shaped shorter process; a single trawl from a depth of 566-644 m.
cluster of spines on the side opposite to the
fold; an obscure third lobe, covered with
Discussion
tiny spines, in—front of the hooked process.
Ethymology. The name of the species Like several other genera included in the
refers to the peculiar arrangement of the Goneplacidae or "Goneplacid-like" group
subapical setae of the male first pleopod, (i.e., Pseudorhombila, Nanoplax, Oediplax,
simulating a—fork {farea). and Chacellus), Bathyrhombila represents a
Remarks. The smaller male features primitive evolutionary step towards a ca-
more marked heterochely, the right claw tometopous stage, in which an uncovered
being about 1.34 times the maximumheight expanded stemite 8 unites to stemite 7. In
1
VOLUME 111, NUMBER 3 639
Fig. 2. Holotype male, CW 24.6 mm, CL 17.5 mm (SIO C-2116). A, dorsal view of carapace; B, dorsal
view ofabdomen and sternal plates 7-8; C, right (upper) (SIO C-2116) and left (lower) claws, frontal view.
the former four genera, the abdominal so- Tavares (1996: 420) note that the size of
mite 2 is: notably reduced, its lateral margin vissible portion of stemite 8 varies among
straight and clearly separated from the coxa specimens of a same species; data related
of P5 (e.g., Oediplax granulata Rathbun, to other genera, however, are lacking. Pseu-
1893, type species of the genus; Pseudo- dorhombila, Nanoplax and Oediplax are
rhombila xanthiformis Garth, 1940; P. oc- considered by Guinot (1969b, 1970) as po-
todentata Rathbun, 1906); reduced but an- tential members of a series of "Goneplaci-
tero-laterally acute, in such a way that the dae" related to the Xanthidae, equivalentto
acute comer is close to the coxa ofP5 (e.g., the Pseudorhombilinae Alcock, 1900.
Chacellus pacificus Hendrickx, 1989a); or Among the species ofPseudorhombila, the
antero-laterally acute and touching the coxa abdomen-sternum organization itself varies
of P5 (e.g., Nanoplax xanthiformis A. from a primitive step (sternites 7 and 8 ap-
Milne Edwards, 1880). In all cases, somite pear not in contact in ventral view, male
2 leaves a reduced portion of stemite 8 vis- opening coxal: P. xanthiformis) to a more
ible at the basis of coxa of pereiopod 5. In advanced phase [sternites 7-8 in contact on
Bathyrhombila the antero-laterally pro- a short distance, in ventral view, displace-
duced corner of somite 2 is almost in con- ment of the male opening towards a sternal
tact with the coxa of P5. In his study of position: P. quadridentata (Latreille, 1828),
Bathyplax typhlus oculiferus Miers, 1886, P. octodentata (Rathbun, 1906), and P.
640 PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON
Fig. 3. Microphotographs (SEM) ofmale first gonopod (Pll). A, B and E, F, paratype, male, CW 22.8 mm,
CL 16.35 mm (LACMNH 68-464.1), slightly damaged, station MV68-I-59, GulfofCalifornia, north ofAngel
de la Guarda Island (29°4rN-113°56"W), Baja California, Mexico, detail of extremity; C, D, holotype, male,
CW 24.6 mm, CL 17.5 mm (SIO C-2116) distal portion (SEM photographs) (scale: A, E lOOX; B, E, 72X; C,
D, 25X).
&
ometlanti Vazquez-Bader Gracia, 1995]; Guinot (1969a, b) is distinguishable in all
this would make Pseudorhombila the most the above mentioned genera (in particular
advanced genus of all. considering the shape of the cheliped) and
The "facies goneplacien" referred to by the pterygostomian ridge, also referred to
VOLUME NUMBER
111, 3 641
by Guinot (1969a, 242) as a ". . . caractere on the PI1 of B. furcata) are also observed
assez constant [in Goneplacidae], rarement on Pll of species of Pseudorhombila and
signale . . ." [a rather constant feature, rare- on the type-species of Nanoplax [i.e., N.
ly reported], is also present in all four gen- xanthiformis (A. Milne Edwards, 1880)]
era (strong and sharp in Oediplax; strong (Hendrickx 1995), with a single cluster of
and granulated in Bathyrhombila; strong to subterminal spines in the later.
moderate in Pseudorhombila; weak in Cha- Another genus close to the "Pseudo-
cellus). In the case ofB.furcata, the general rhombilid" organization is Euphrosynoplax
aspect of the crab relates it to species of Guinot. The visible portion of stemite 8,
Pseudorhombila; the carapace is similar, however, is smaller in E. clausa (the type-
notably wider than long, with distinguish- species of the genus) than in Pseudorhom-
able regions and convex in lateral view. bila, Bathyrhombila and Oediplax; and is
Both genera feature large to very large similar in size to stemite 8 of Nanoplax
(Bathyrhombila), heavy chelipeds, although xanthiformis and the two known species of
the heterochely is more marked in Pseu- Chacelus.
dorhombila. Orbits and eyes are small. When all these species are compared,
Structure of the frontal and antennular they present striking similarities as far as
regions and ofthe bucal frame is similar, as their general shape and aspect is concerned.
is the shape of the third maxilliped, al- On the basis of these considerations, and
though the antero-lateral angle ofthe merus following the suggestion of Guinot (1970;
is not so produced inBathyrhombila (in this 1080), the use of the family-group name
respect, closer to Oediplax). Both genera Pseudorhombilidae Alcock, 1900, is pro-
also feature long (Pseudorhombila) to very posed for those genera of "goneplacid-xan-
long (Bathyrhombila), flattened, slender thid" crabs.
P2-P5. Bathyrhombila, however, differs
from Pseudorhombila in the following Pseudorhombilidae Alcock, 1900
characters: the exorbital and second teethof
Pseudorhombihnae Alcock, 1900:286, 292,
carapace are fused, forming a wide, almost
straight slightly projecting margin (exorbi- 297, pro parte. —
Pseudorhombilinae. Guinot, 1969b:706;
tal tooth almost wanting in Pseudorhombi-
1971:1080.
la); the pterygostomian ridge, in front of —
the cheliped articulation, is much stronger Type genus. Pse—udorhombila.
in Bathyrhombila; the second abdominal Included genera. Bathyrhombila new
segment is wider in Bathyrhombila; and the genus, Chacellus, Euphrosynoplax, Nano-
structure of the male Pll is strikingly dif- plax, Oediplax—, and Pseudorhombila.
ferent (Fig. 3). Considering the shape ofthe Definition. Carapace xanthoid, wider
male gonopods, the slender Pll of Bathy- than long, with 3-5 (including outerorbital)
rhombila is closer to Pll of Chacellus antero-lateral teeth. Bucal frame widening
(Pseudorhombila and Oediplax possess a anteriorly. Orbits of moderate or reduced
shorter, more massive Pll). Ornamentation size, oval. Chelipeds goneplacids, long,
of the tip of Pll however, shows affinities heavy, with long, strongly to moderately in-
with some species of Panopeidae Ortmann, curving fingers. Pterygostomian ridge (in
1893 such as Lophopanopeus frontalis front of chelipeds) strong to moderate. Ab-
Rathbun (see Martin «fe Abele 1986: fig. dominal somites 3-5 at leastpartiallyfused,
IN). Although the "third" lobe (typical of sutures usually visible. Second abdominal
Panopeidae) in Bathyrhombilafurcata, new somite reduced, its antero-lateral margin in
species is hardly distinguishable, the other contact with (anterior angle produced) or
two processes are strongly developed. In separated (margin straight) from basis of
contrast, long subterminal spines (present coxa of P5. Sternal plate wide and slightly
642 PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON
to moderately depressed between PI (min- Provisional key to genera of
imum width between PI equal to 0.60-0.63 Pseudorhombilidae
times maximum width between P2). A
small to relatively large piece of stemite 8 1. Distance between outer orbital and first
anterolateral teeth much shorter than or-
visible ventrally; stemite 8 not touching
bit width; these tooth partially-fiised,
stemite 7 in ventral view (PU coxal) or in
separated by a shallow notch. Extremity
contact over a short distance (PU displaced of male PU with a strong longitudinally
towards a sternal position). PU long and projecting flange Nanoplax
slender or moderately long and strong; or- - Distance between outer orbital and first
namentation variable. P12 short, strongly or anterolateral teeth about equal to orbit
moderately sigmoid. width 2
—
Genera. The family is divided into 2. Pll of male long, very slender and ta-
three groups of genera. Group A includes pering, with only a few minute spines
the most primitive catometopous forms along the shaft Chacelus
(i.e., Nanoplax, Chacellus, Bathyrhombila - Pll of male stout, strong, twisted, with
and Euphrosynoplax); group B includes median to large spines along the shaft
and distal part 3
species with a larger visible piece of ster-
3. Outer orbital and first anterolateral teeth
nite 8 {Pseudorhombila pro parte and Oed- coalesced, forming an almost straight
iplax); group C includes species with alarg- slightly projecting margin. Extremity of
er visible piece of stemite 8 in contact over male Pll with two longitudinal series of
a short distance with sternite 7 {Pseudo- very long spines Bathyrhombila
rhombila pr—o parte). - Outer orbital and first anterolateral teeth
Remarks. Among the Pseudorhombili- reduced, separated by a granulated
dae, several species present a subtriangular space; granules coarse to minute 4
hiatus between the ischium and the merus 4. Merus ofMXP3 notproduced antero-lat-
of the third maxilliped (e.g., Chacelluspa- erally Oediplax
- Merus of third maxilliped strongly pro-
cificus; both species of Euphrosynoplax;
duced antero-laterally 5
Oediplax granulata; Pseudorhombila xan-
5. Extremity ofmale Pll with a strong sub-
thiformis, P. quadridentata and P. guinotae terminal or lateral upturned flange; a
Hernandez-Aguilera, 1982) while otherspe- patch of strong spines just below the
cies (e.g., Chacellus filiformis Guinot, flange and series ofweaker spines along
1969b; Pseudorhombila ometlanti) possess shaft Pseudorhombila
an anteriorly expanded lobe at the inner an- - Extremity of male Pll with a lateral
gle of the ischium that makes contact with flange; no patch of strong subterminal
the proximal margin of the merus (Hen- spines below the flange, but a series of
drickx 1989a: table 1). The third maxilliped moderate size spines along the shaft . . .
Euphrosynoplax
ofother species have not been illustrated in
the literature and specimens have not been
available for examination. In Nanoplax, the Relationships between Pseudorhombili-
partially-fused outerorbital and secondteeth dae Alcock and the Panopeidae Ortmann
are much narrower than in any other genus are difficult to establish. As emphasized by
included in the Pseudorhombilidae, al- Guinot (1969a:249, 250, and in fit.) this is
though still separated by a shallow notch. due basically to the complexity of the Pan-
The carapace of species ofPseudorhombila opeidae sensu lato, of which a first group
and Oediplax features a reduced to uncon- presents a xanthid facies and coxal male
spicuous first anterolateral tooth and the opening (e.g., Eurypanopeus, Panopeus),
fifth tooth varies from well (e.g., P. octo- while a second group presents a goneplacid
dentata) to poorly developed (or obsolete) facies and coxal or coxo-sternal male open-
(e.g., P. quadridentata). ing (e.g., Cyrtoplax, Glyptoplax). Some
VOLUME NUMBER
111, 3 643
—
species of the Panopeinae second group Grapsoidea. Journal of the Asiatic Society of
(e.g., Glyptoplax pugnax Smith, 1870, the Bengal 69. 2(3):279-456.
Balss, H. 1957. Decapoda. In Dn H. G. Bronns Klas-
type species of the genus, and G. consagae —
sen und Ordnungen des Tierreichs. Fiinfter
Hendrickx, 1989b) present a sternum-ab- Band, 1. Abteilung, 7. Buch, 12. Lief: 1505-
domen organization more advanced to- 1672.
wards a catometopous organization, with Garth, J. S. 1940. Some new species of brachyuran
uncovered section of sternites seven and crabs from Mexico—and Central and South
eight widely in contact and covering a American mainland. Allan Hancock Pacific
Expeditions 5(3):51-127.
groove through which the penis passes (see
Guinot, D. 1967. Recherches preliminaires sur les
Hendrickx 1989b: 653). All members ofthe groupements naturals chez les Crustaces Deca-
Panopeidae, including Glyptoplax, howev- podes Brachyoures. Les anciens genres Micro-
—
er, feature the typical "Panopeid" PU or- panope Stimpson et Medaeus Dana. Bulletin
namentation. du Museum National d'Histoire Naturelle, 2e
Ser. 39(2):345-374.
Specimens of the monospecific genera
. 1969a. Recherches preliminaires surles grou-
Thalassoplax Guinot and Robertsella Guin- pements naturels chez les Crustaces D—ecapodes
ot were not available during this study. Brachyoures. VII. Les Goneplacidae. Bulletin
Both genera were briefly described by du Museum National d'Histoire Naturelle, 2e.
Guinot (1969b) to accomodate specimens Ser. 41(l):241-265.
erroneously identifiedby Rathbun (1918) as . 1969b. Recherches preliminaires surles grou-
pements naturels chez les Crustaces Decapodes
Pilumnoplax elata (A. Milne Edwards,
Brac—hyoures. VII. Les Goneplacidae (suite et
1880). Both genera are very similar primi- fin). Bulletin du Museum National d'Histoire
tive catometopous and feature distinctive Naturelle, 2e. Sen 41(3):688-724.
male Pll. Shape of carapace (see Guinot . 1970. Recherches preliminaires sur les grou-
1969: plate V) ofboth genera is apparently pements naturels chez les crustaces—brachy-
oures. VIII. Synthese et bibliographic. Bulle-
different from typical pseudorhombilids tin du Museum National d'Histoire Naturelle,
(carapace more squarish; wider front and Paris, 2e. Ser. 5:1063-1090.
orbits). Further studies will be needed to . 1977. Donnees nouvelles sur lamorphologic,
show if these two genera belong to the la phylogenese et la taxonomie des Crustaces
Decapodes Brachyoures. These de Doctorat
Pseudorhombilidae or not.
d'Etat es Sciences, soutenue le 21 juin 1977 a
Acknowledgments rUniversitePierre-et-Marie-Curie. 2vol.infol.,
p. I-XV, 1-486, XVI-XXIV, 56feuillesn.n., 78
The author thanks W. Newman and L. Fig., 31 pi., 2 Fig. n.n., 14 tabl.
Spencer, Scripps Institution of Oceanogra- . 1978. Principes d'une classification evo—lutive
phy, for the loan of the specimens. Com- des Crustaces Decapodes Brachyoures. Bul-
letin Biologique de la France et de la Belgique
ments and suggestions provided by D.
112(3):2I1-292.
Guinot, T. Tavares and R. Lemaitre greatly . 1979. Donnees nouvelles sur la morphologic,
helped to improve the manuscript. A. Es- la phylogenese et la tax—onomie des Crustaces
parza-Haro helped with some ofthe figures. Decapodes Brachyoures. Memoires du Mu-
M. Cordero edited final version of the seum National d'Histoire Naturelle, Paris. Ser.
manuscript. SEM Figure 3 C, D were pre- A, Zoologie 112:1-354.
Hendrickx, M. E. 1989a. Chacelluspacificus, newspe-
pared and taken at Scripps Institution of cies (Crustacea: Decapoda; Brachyura: Gone-
Oceanography and are courtesy of C. Gra- placidae) from the conti—nental shelfofthe Gulf
ham; Figure 3A, B, E, F were prepared and of California, Mexico. Bulletin du Museum
taken at the Institut Royal des Sciences Na- National d'Histoire Naturelle, Paris. Ser. 4, 11,
turelles de Belgique by F Fiersand J. Cillis. A(l)1:98199b1.-20G0l.yptoplax consagae new species
.
(Crustacea: Decapoda: Brachyura: Panopeidae)
Literature Cited
from the GulfofCalifornia, Mexico, withsome
Alcock, A. 1900. Materials for a Carcinological fauna notes—on the distribution of G. pugnax Smith,
of India. No. 6. The Brachyura Catametopa of 1870. Bulletin du Museum National