Four new genera for northeastern Pacific gastropods

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THE NAUTILUS 114(3):99-1()2, 2()()() Page 99
Four new genera for northeastern Pacific gastropods
James H. McLean
Natural Histors' Museum of Los
Angeles Counh'
900 Exposition BKd.
Los Angeles. CA 90007 USA
[email protected]
ABSTRACT SYSTEMATICS
Four new genera for nortlieasteni Pacific Gastropodaare pro- Family Velutinidae Gray, 1840
posed; V'elutinidae: Torcllivclutina. type species "Torellia"am- Genus Torcllivclutina new genus
monia Dall, 1919; Euliniidae; Subniso. type species "Chemnit-
zia" ranai de Folin. 1867; Turridae. Clathurellinae; Retidrillia. Type species: "Torellia" ammonia Dall, 1919 (Figure
tspe species "Suavodrillia" willctti Dall. 1919; Mangeliinae; 1). The shriveled liolotvpe from offshore depths at the
PcrimangeUa. t\pe species "Mangelia" intcrfossa Carpenter, Aleutian Islands, Alaska, was illustrated byWaren (1989:
1864. 16, fig. llf). A more recently collected, preserved spec-
Additional kci/ words: Gastropoda, Euliniidae, Turridae, V'e- imen from the Aleutian Islands is illustrated here.
lutinidae. Included species: The genus is monotypic.
mm
Diagnosis: Shell large (to 30 diameter), apical
INTRODUCTION whorl depressed, profile nearlyplanispiral, oftwo rapidly
inflated whorls, calcareous layer lacking in large speci-
This is the third in a series ofpapers in which new gen- mens except for that which borders the apertural hp;
era for northeastern Pacific gastropods are introduced shemllmconsisting ofchitinous periostracum after attaining
(see McLean, 1995a, b). I had prexaously indicated (Mc- 3 diameter; protoconch with spiral sculpture (ac-
cordingto original description ofDall); suture deep, um-
Lean, 1995a) that a checklist ofthe northeastern Pacific
gastropods was in preparation; however, as indicated in bilicus broad; mature surface composed ofthick, chitin-
McLean (1996: 2), I am preparing a more complete ous, colabral a.xial lamellae.
work rather than a checklist. Taxa described here are to Remarks: Waren (1989: 16) examined the type spe-
be used in an illustrated rexasion of all shelledgastropods cies for purposes ofcomparison with his then described
of the northeastern Pacific, ranging from Arctic Alaska new genus and species Pscudotorclliafragilis from Ice-
and the Aleutian Islands to central I3aja Cahfomia, Mex- land. He illustrated the radula of "Torellia" ammonia
ico. Description ofthese genera in advance ofthe book (op. cit., fig. IIC), which he found to agree with that of
allows for a more detailed treatment than will be pos- othervelutinid radulae, and reported that theoperculum
sible in the larger effort. Further papers in this series and other trichotropine features are lacking. Although
will describe genera in which the tyjie species or other Waren removed "T." ammonia from the trichotropid ge-
included species are new. nus Torellia, and transferred it to the Velutinidae, he did
To distinguish original combinations for type species not assign it to a genus. Torellivehitina is therefore here
of the new genera I am here using the convention of proposed for "T" ammonia. It differs from Pseudotorcl-
placing all citations of original genera within quotation lia in not having a sohd calcified shell with spiral sculp-
marks. Illustrations are proxaded here for type species of ture and not having the large, projecting protoconch of
each new genus.
Pseudotorellia.
Although monotvpic genera are not encouraged in Because the calcareous layer is lacking, fresh speci-
phylogenetic classifications, I do not refrain from intro- mens of Torellivehitina ammonia should be retiiined in
ducing a few such genera where necessarv-, allowing that fluid preservative and should not be dried, which results
additional living or fossil species may yet be discovered in the shrinkage and buckling of the thick periostracal
that would render those genera no longer monotypic.
layer.
Museum acronvms are: LACM, Natural History Mu-
seum ofLos Angeles Counb,'; USNM, National Museum Etymology: The name is a compound of the tricho-
of Natural History, Washington. tropid genus Torrellia and the velutinid genus Vclutirm,
Page 100 THE NAUTILUS, Vol. 114, No. 3
A
Figures 1^. T)pe species of new genera. 1. Torellivehttina ammonia (Dall, 1919), apertural and spire views. LACM 152281,
Kanaga Pass, between Kanaga Island and Tanaga Island, AndreanofIslands, Aleutian Islands, Alaska, 61 ni. Maximum diameter.30
mm. 2. Subniso rangi (de Folin, 1867). LACM 1972-38.7, Punta Penca, N of Bahia Potrero, Guanacaste Pro\., Costa Rica, 10 ni.
Length 3.2 mm. 3. Retidrillia willetti (Dall, 1919). USNM 216409, lectotype. Forrester Island, southeasteam Alaska, dredged.
Length 11.5 mm. 4. Perimangelia inferfossa (Carpenter, 1864). LACM 1959-13.42, Granite Creek, Monterey County, California,
10 m. Length 8.5 mm.
to emphasize that it represents a velutiiiid with the su- whereas most species of the genus have a shell that is
mm
perficial aspect of the trichotropid genus Torrellia. 10-30 high, occasionally even higher." Additionally,
I point out that Niso species are usually broadly umbil-
Family Euhmidae Philippi, 1853 icate, except for the large N. atiilloi (Hertz and Hertz,
Genus Subniso new genus 1982), usually not angulate at the base, and have color
patterns that may be banded or variegated. Taken to-
gether, these differences are sufficient to justify' generic
Type species: "Chemnitzia" rangi de Fohn, 1867
recognition of Subniso.
(Figure 2). Type locality: Perlas Islands, Panama. Waren Waren (1992: 1S3) noted that a starfish host is known
(1992: 183) could not locate type material, but the spe- for one Indo-Pacific species of Niso, but nothing is
cies was well figured bv de Folin and subsequently by known of the host echinoderm for the two species of
Waren (1992, figs. 17, 20-22, 25-27, 30, 31), so there is Subniso.
little doubt as to its identity. The species occurs from
southern Baja Cahfomia, Mexico, to Ecuador. Etymology: The generic name combines the generic
name Niso, with the prefix sub-, to emphasize the small
Included species: Two species, the type species and size, compared to Niso.
"Niso" hipolitcnsis Bartsch, 1917, forwhich the holotype
from Punta San Hipohto, Baja California, Mexico, was
illustrated by Emerson (1965, fig. 9) and Waren (1992: Family Turridae Swainson, 1840
figs. 19, 23, 24). Both species have previously been Subfamily Clathurelhnae H. and A. Adams, 1858
placed in Niso Risso, 1826, bv Emerson (1965) andWar- Genus Rctidrillia new genus
en (1992).
Type species: Suavodrillia" willetti Dall, 1919 (Fig-
Diagnosis: Shell small (length to 4 mm), slender '
ure 3). Type locality: Forrester Island, Southeast Alaska.
(length to breadth ratio 2.5-2.9), non-umbilicate, basal Until now the species has been unfigured (it was not
angulation pronounced, coloration brown, without color
illustrated by Kosuge, 1972). The here selectedlectotype
pattern. (Figure 7) is the largest (11.3 mm) ofseven original syn-
Remarks: The two species ofSubniso are unUke other type specimens in the type lot. The radular tooth ofthe
species of Niso in size, profile, and color. The two spe- type species was figured by McLean (1971, fig. 114)
cies are small, non-umbilicate, and have a basal angula- (from LACM 66-66, Graham Island, Queen Charlotte
tion (strongly projecting in Subniso rangi) and auniform Islands, British Columbia). A specimen from the Rae
LACM
brown coloration. Waren (1992: 185) remarked: "Both Baxter collection in the extends the distribution
Niso hipolitcnsis and N. rangi are unusual among the to Akutan, Aleutian Islands (LACM 83-345. 263 m
3^ mm
species ofNiso in their small size, shell height, depth).
H. McLean, 2000 Page 101
J.
Included species: At least three species, the t\pespe- 30-4). Synonym: "Man^elia" interlirata Stearns, 1872.
cies and two species from the northeastern Atlantic dis- The species occurs from Clallnm County, Washington,
cussed and illustrated bv Bouchet and Waren (1980: 32) to Isla San Ceroninio, Baja Cahfomia, Mexico, based on
in the genus Drilliola Locard, 1897: "D." pntina (Wat- specimens in the LACM collection.
son, 1881), and "D." megalacmc (Sykes, 1906).
Included species: Two species, the type species and
Diagnosis: Shell profile with concave shoulder and the less familiar "Manficlia" nitcns Carpenter, 1864 (syn-
projecting peripheral carination below which base is type figured by Palmer, 1958, pi. 28, fig. 1). It ranges
rounded and has strong spiral sculpture. Anal sinus on from Sonoma County, California, to Ensenada, BajaCal-
concave shoulder, deep and broad. Axial sculpture ex- ifornia.
pressed as nodes, strongest at peripheral carination,
Diagnosis: Shell relatively small and slender with
more f;iintlv expressed on strong spiral cords of base.
dominant axial sculpture, crossed by narrow spiral cords
Peripheral carination of early whorls at midvvhorl. Pro-
of lesser strength. Protoconch of 1.5 whorls, strongly
toconch paucispiral, with early development of periph-
projecting, smooth at first, developing fine spiral sculp-
eral carination. Radular tooth long, haqioon-like, with
ture after first half whorl, followed by weaker axials (ax-
broad base.
ials more numerous than that of mature sculpture),
Remarks: The type species was described in the ge- changing imperceptibly to adult sculpture.
nus SiiavodriUia Dall, 1918 (tvpe species: "Drillia" kcn-
nicotti Dall, 1871), with which it shares the long har- Rtyepmearskpesc:iesEoafrltiheer n(MecwLegaenn,us19(7"8M:ang74e)l,iaI"pilnatccerfdostshae)
poon-like radular tooth. Dall (1921: 69) indicated doubt
along with "Daphnclla"ftiscoligata Dall, 1871 in Clatli-
mthaartk"Sp.r"ecweildlienttgi twhaesgceonnugse.neDriifcfebryenpcleascianrgeathqautesRteitoin- romangclia Monterosato, 1884. I now consider Clath-
romangclia (type species "Plcurotoma" grantiin Philippi,
drillia iLillctti and the tvvo additional species here as- 1844; see Powell, 1966: 106) to be appropriate for two
signed to the genus are half the size of S. kcnnicotti, and species in southern Cahfomia: "Daphnclla" fuscoligata
have sculpture that is axial and spiral, rather than strictly and "Mangilia iClafhmmangclia)" rhi/ssa Dall, 1919.
spiral as in SiiavodriUia. The newly restricted Siiavod-
These two species have coarse clathrate sculpture and
riUia is monot\pic for S. kcnnicotti, a species broadly
relatively low, paucispiral protoconchs.
distributed in the north Pacific from Hokkaido, Japan,
Pcrimangclia differs from the two species of Clath-
the Kurile and Aleutian Islands, and the Gulf of Alaska
romangclia in having numerous, narrow spiral cords
to Southeastern Alaska.
overriding the dominant axial ribs, rather than having
Bouchet and Waren (1980: 32) retained "a wide va-
coarsely clathrate sculpture with nodes at intersections.
riety of species" in Drilliola, including those that 'look
Protoconchs differ: the paucispiral protoconch of the
rather different but have a similar radula and opercu-
lum." They elected "to keep them in Drilliola rather wthweoresapsectihees poafuciPscpirriamlanpgrcoltioacoinschstorfontghley tpwroojsepcetciinegs,
than placing them in any of the perhaps more similar, of Clathromangclia is much lower.
but anatomically unkiiown genera hsted by Powell
(1966) in different subfamihes. Species tvpical ofDril- Etymology: The name combines the prefix pcri-
'
liola are more slender than those of Rctidrillia and do (near) with Mangelia Risso, 1826, one ofdie oldest gen-
not ha\e the broad, excavated shoulder. The proposal of era in the subfamily Mangeliinae.
Rctidrillia thus provides a genus with a type species hav-
ing knowii radular characters for the two species cited ACKNOWLEDGMENTS
by Bouchet and Waren (1980).
On shell characters, Retidrillia resembles species as- Photographic prints were made by Michael Eraser. I am
signed to Plicisifrinx Sysoev and Kantor, 1986, in which grateful to Lindsey Groves, Daniel Geiger, Anders War-
the radular tooth is of the modified wishbone t)pe, in- en, and a further anonymous reviewer for offering help-
dicative of the less derived turrid subfamily Cochlespi- ful suggestions.
LITERATURE CITED
Etymology: The name is a compound of rcti-, mean-
ianngdnDerti,llwiiathGrraey,fe1r8e3n8c,e otonethoefatxhiealeaarnlidesstpinraalmsecdulopftutruer,- BouchAettla,ntPi.cabnadth\Aa.lWaanrdena.bys1s9a8l0.TuRrerviidsaieon(Moolflvtihseca,noGratshteraos-t
rid genera. poda). Joiinial of Moiluscan Studies, Supplement8:1-119.
Dall, W. H. 1919. Descriptions ofnew species ofmollusks of
Subfamily Mangehinae Fischer, 1883 tlie family Turritidae from the west coast ofAmerica and
Genus Pcrimangclia new genus adjacent regions. Proceedings of the United States Na-
tional Museum, 56(2288):1-86, pis. 1-24.
Dall, VV. H. 1921. Summary of the marine shellbearing mol-
Type species: "Mangelia" intcrfossa Caqienter, 1864 lusks ofthe northwest coast ofAmerica, from San Diego,
(Figure 4). Syiitypes were figured by Palmer (1958, pi. Califoniia, to the Polar Sea, mostly contained in the col-
27,'figs. 5, 6)' Also figured by McLean (1969; 1978, fig. lection ofthe United States National Museum, with illus-
Page 102 THE NAUTILUS, Vol. 114, No. 3
tratdons of hitherto unfigiired species. United States Na- replacement names for northeastern Pacific prosobranch
tional Museum, Bulletin 112, 217 pp., 22 pis. gastropods. The Nautilus 108:80-83.
Emerson,W. K. 1965. Theeastern PacificspeciesoiNiso(Mol- McLean, J. H. 1996. The Prosobranchia. In: P H. Scott, J. A.
lusca: Gastropoda). American Museum Novitates2218:1- Blake, and A. L. Lissner (eds.) Taxonomic atlas of the
benthic faunaofthe Santa Maria Basin andwestern Santa
12. —
Kosuge, S. 1972. Illustrations of type specimens of molluscs GBaasrtbraorpaodCah.annSaenlt.aVBoalrubmaera9.MuThseeuMmoUoufsNcaatuPraarlt H2istTorhye,
described bv William Healev Dall (Northwestern Pacific
Santa Barbara, v -t- 160 pp.
gastropods). Special publication of the National Science Palmer, K. V. W. 1958. Type specimens of marine Mollusca
Museum, Tokyo, 29 plates and unpaged captions. described by P. P. Carpenter from the west coast (San
McLean, J. H. 1969. Marine shells ofSouthern California. Los Diego to British Columbia). The Geological Society of
Angeles County Museum ofNatural History, Science Se- America, Memoir 76, vi -I- .376 pp., 35 pis.
ries, no. 11, 104 pp. Powell, A. W. B. 1966. The molluscanfamiliesSpeightiidaeand
McLean, H. 1971. A revised classification ofthe familyTur- Turridae. Bulletin ofthe Auckland Institute and .Museum,
J.
ridae, with the proposal of new subfamilies, genera, and no. 5, 184 pp., 23 pis.
subgenera from the Eastern Pacific. The V'efiger 14:114- Sysoev, A. V. and Y. 1. Kantor. 1986. [New and rare abyssal
species ofthe tamilvTurridae (Gastropoda, Toxoglossa)in
130.
the northern part of the Pacific Ocean.] Zoologicheskii
McLean, H. 1978. Marine shells of.southern California, Re-
visedJ.edition. Natural Histors' Museum of Los Angeles WarenZ,huAm.al1,9896.5(1N0e):w14a5n7d-1li4t6tl9e.kn[IonwnRusMsoilalnu]sca from Iceland.
County, Science Series, no. 24, 104 pp. Sarsia 74:1-28.
McLean, J. H. 1995a. FournewgenerafornortheasternPacific Waren, A. 1992. Comments on and descriptions of eulimid
prosobranch gastropods. The Nautilus 108:39-41. gastropods from Tropical West America. The Veliger 35:
McLean, H. 1995b. Three additional new genera and two 177-194.
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