The genus Avenionia Nicolas, 1882, redefined (Gastropoda, Prosobranchia, Hydrobiidae)

12 Pages·2000·2.2 MB·English

by  Bodon, Marco

BASTERIA, 64: 187-198, 2000
The genus Avenionia Nicolas, 1882, redefined
(Gastropoda, Prosobranchia, Hydrobiidae)
Marco Bodon
Dipartimento di BiologiaEvolutiva dell'Universita di Siena, Via P.A. Mattioli 4, I 53100 Siena, Italy
Simone Cianfanelli
Museo Zoologico de "La Specola", Sezione del Museo di Storia Naturale dell'Universita di Firenze,
ViaRomana 17, I 50125 Firenze,Italy
Giuseppe Manganelli
Dipartimento di Biologia Evolutiva dell'Universita di Siena, Via P.A. Mattioli4, I 53100 Siena, Italy
Henri Girardi
3, Rue de l'Hymne au Soleil,Les Sylphides, F 84140, Montfavet,France
& Folco Giusti
Dipartimento diBiologia Evolutiva dell'Universita di Siena, Via P.A. Mattioli 4, I 53100 Siena, Italy
Anatomicalstudy ofspecimens ofthe type speciesofAvenionia,Avenionia vayssieri Nicolas, 1882
(junior synonym ofPaulia berenguieri Bourguignat, 1882,currently A. brevis berenguieri), from
southern France,revealedcharacters different fromthoseknown in theavailableliteratureand
prompted the redefinition ofAvenionia. The otherAvenioniaspeciesfrom France andnearby
countries ofcentral-western Europearetentativelyleft in this genus,whereas taxafromItaly
which wereincluded inAvenionia on formerly available evidence will have tobe assigned to
another genus.
Key words: Gastropoda, Prosobranchia, Hydrobiidae,Avenionia,France, Europe,taxonomy.
INTRODUCTION
Thetype species ofAvenionia, Avenioniavayssieri Nicolas, 1882,junior synonymofPaulia
berenguieri Bourguignat, 1882 (Boeters, 1967; Kabat & Hershler, 1993), was unknown
anatomically sothatthe diagnosis ofthegenus was basedonallegedly relatedtaxa from
central-western Europe. The recent finding ofliving specimens closely matching the
188 BASTERIA, Vol. 64, No. 4-6, 2000
lectotype selected by Boeters (1967) in asite nearthetype locality, prompted anatomical
study which revealed characters different from those reported for the species/genus
(Boeters & De Winter, 1983; Boeters, 1998).
Thispaper redescribes the type species, redefines the genusAvenioniaand analyses the
relationships between the French, central-western European and Italian taxa hitherto
included in this genus.
MATERIALS AND METHODS
Shells and live specimens were collected with a net and by sorting sediment from a
subterraneanspring. Shells and radulae (obtained by dissecting out buccal bulbs and
washing indistilledwater)were mountedon copperblocks with conductiveglue, sputter-
coated with gold and photographed using a Philips 515 SEM. All dimensions (shell
height, shell diameter, aperture height and aperture diameter) were measured using a
micrometer lens on the light microscope (Wild MSA). Unrelaxed material preserved
in 80% ethanol was studiedby light microscopy (Wild MSA). Bodies were isolatedafter
crushing the shells and were dissected using very fine pointed watchmaker's forceps.
Images ofthewhole body and isolatedparts ofthe genitalia were drawn using a Wild
camera lucida.
The materialstudiedis deposited inthefollowingcollections:MuseoZoologico de"La
Specola" (Sezione del Museo di Storia Naturale dell'Universita di Firenze, Firenze,
Italy; MZUF), F. Giusti (Dipartimento di Biologia Evolutiva dell'Universita, Siena,
Italy), M. Bodon (Via delle Eriche 100/8, Genova, Italy), S. Cianfanelli(P.le Porta
Romana 13, Firenze), and H. Girardi (Montfavet, France).
REDESCRIPTION AND TAXONOMIC STATUS OF AVENIONIA VAYSSIERI
NICOLAS, 1882, A JUNIOR SYNONYM OF PAULIA BERENGUIERI BOUR-
GUIGNAT, 1882
Description. Shell(figs 1-11) very small, cylindro-conical, bythinelloid, waxen,
whitish and translucent when fresh; apex rather acute; spire consisting of 33A-4 %
convex whorls; last whorl wide, 2/3-3/4 ofshell height; sutures very deep; aperture
rather small, ovaland slightly oblique;peristome thin,continuous,adhering to lastwhorl
or slightly detached, not reflected andnot sinuous, butsometimes very slightly concave
(in lateral view) at upper external margin; umbilicus variably narrow, slit-like; surface
ofprotoconch finely malleated; surface of teleoconch rather smooth, with more or less
evident growth lines and very finely malleatedon the first whorls.
Dimensions. - - Shell height, 1.55-2.89mm; shell diameter, 0.81-1.29mm; aperture
height, 0.62-0.97 mm; aperture diameter, 0.46-0.75 mm.
Operculum (fig. 12). Corneous,paucispiral, thin,pale yellowishincolour, yellowish-
orange at centre,with subcentralnucleus andwithoutprojection or thickening on inner
side.
Body (fig. 13). - Almost unpigmented, traces ofpigment only on walls ofvisceral
sac; eye spots small; pallial tentacle absent. Sparse whitish granules in walls of body
and foot; group ofwhitish granules behind base ofeyes; buccal mass, body and base
oftentacles intensely pink coloured(all thesedetailsarevisibleonly inliving specimens).
Male genitalia (figs 14-18). Testis nearapex ofvisceral sac, with many lobes;
Bodon et ai:Avenionia redefined 189
Figs 1-8. Shells ofAvenionia brevisberenguieri(Bourguignat, 1882),collectedinthe springofthefountain ofSt.
Victor-la-Coste (Gard, France). Scale bar 1 mm.
vas efferens thick, functioning as seminal vesicle; prostate gland elongated, its distal
portion bulging slighdy into pallial cavity; vas deferens thin, arising from anterior side
ofprostate gland, crossingbody wall,entering baseofpenis andrunning (as penial duct)
all along right (outer) side ofpenis to end at tip ofpenis proper; penis unpigmented,
bentuponitselfinsidepallial cavity, squat,withsideswrinklednearbase; penis withapex
bifid, dividedinto very large subapical lobe and slender tip ofpenis proper; subapical
190 BASTERIA, Vol. 64, No. 4-6, 2000
Figs 9-11. Microsculpture ofsurface ofprotoconch(fig.9, lateralview; fig. 10,upper view) andteleoconch
onthe lastwhorl (fig. 11)ofAvenionia brexisberenguieri(Bourguignat,1882),collected inthe springofthefountain
ofSt. Victor-la-Coste (Gard,France). Scale bar 50µm.
lobe with three glandular swellings along its border, one short, the others long, band-
like and sinuous; anothervery small, glandular lobe on dorsalsideofpenis closeto base
of subapical lobe; tip ofpenis proper conical, slender and pointed, about as long as
penial lobe.
Female genitalia (figs 19-21). Ovary near apex of visceral sac, lobed; short
gonadal oviduct, ending where gonopericardial duct enters gonadal oviduct and renal
oviduct begins; renal oviduct adhering to pallial oviduct, wide, twisted onitselfto form
short loop; two seminalreceptacles: proximal seminal receptacle (RS2) arising beyond
end of loop, larger than distal and with evident, slender duct; distal seminalreceptacle
(RSI) small, without evident duct, arising very close to where duct ofbursa copulatrix
enters oviduct, but situatedrather close to proximal one; bursa copulatrix very large,
shaped like an oblong sac, anterior(distal) side ofwhich adheres closely to posterior
(proximal) side ofalbumen gland portion ofpallial oviduct and posterior (proximal)
portion ofwhich extendsfar beyond site ofproximal seminalreceptacle (inside visceral
sac); bursa copulatrix duct very short, anteroventral; pallial oviduct bulging well into
pallial cavity and consisting ofalbumenand capsule glands, its opening (female gonop-
ore) small, situatednotfarfrompallial margin; ventral sideofpallialoviduct withventral
groove.
Radula(figs 22-27). - Taenioglossate consisting ofmany rows ofseven teeth, each
with the following formula: C = 6+l+6/1+ 1;L= s+l+5-6= 11-12;Ml =27-30; M2
=22-25. Centraltooth trapezoidal withlong slenderlateralwings; body extendedtoform
basal tonguewedged in concave apex ofadjacent central tooth; apical margin V-like,
with row of 13 denticles, central longer than laterals; one basal cusp arising between
baseofeachlateral wingandbody oftooth. Lateral teethwithbody elongated; anterior
margin with 11-12 denticles, central longer than laterals. Inner marginal teeth rake-
like, with elongated body and long apex with row of 27-30 denticles along anterior
margin. Outermarginal teethspoon-shaped, with22-25 denticlesonouterlateral margin
ofapex.
Stomach and intestine(figs 14, 19). - Stomach with rudimentary gastric caecum.
First portion ofintestinerunning adjacent to wallofstyle sac beforeforming U-like loop
Bodon et ai:Avenionia redefined 191
near stomach; loop on pallial wall absent or poorly defined; rectal portion ofintestine
straight; anus at pallial margin.
Pallialorgans (figs 14, 19). - Osphradium oval orkidney-shaped, shortor slightly
elongated; ctenidium consisting of 17-31 lamellae; pallial tentacle absent.
Materialexamined. - Spring ofthe fountainofSt. Victor-la-Coste (Gard, France)
(for a description ofthe biotope, see Girardi, 1990),M. Bodon, H. Girardi& B. Bomba
leg., 29.xii.1998 (7 males, 5 females, many shells and undissected specimens).
Taxonomy. Stygobiont hydrobiids living in the wells of"Rue deVelouterie, n°
9" at Avignon (Dep. Vaucluse, France) were discovered by M.H. Nicolas in the 1870s.
In May 1881, Nicolas gave material ofthese species to somebody [P. Berenguier ?]
charging him toaskJ.R. Bourguignat foran opinion (Nicolas, 1882: 161). Injune 1881,
Nicolas readapaper at theAcademie deVaucluse onthenew genus Avenionia(Fischer,
1885: 34). InMay 1882,Bourguignat published apaper(Bourguignat, 1882) inwhich
heintroducedthenew genus PauliaBourguignat, 1882,andtwo newspecies (P. berenguieri
Bourguignat, 1882, and P. locardianaBourguignat, 1882) basedonmaterialreceivedfrom
P.Berenguier, butactually discoveredby M. Nicolas. Nicolasheardaboutthis and gave
a detailedexplanation (Nicolas, 1882: 161, and note 1) ofthe events which preceded
the publication ofBourguignat's paper (1882) claiming never to have renounced his
rights to the discovery (" ... me reservant, bien entendu, tousles droitsque ma decou-
verte m'accordait"). Nicolas's paper, published in the Memoires de l'Academie de
Vaucluse (Nicolas, 1892), contains the description ofthenewgenusAvenioniafortwonew
species: Avenionia vayssieri Nicolas, 1882, and A.fabri Nicolas, 1882. Another species
named and described by Bourguignat in his letter to Nicolas, A. lacordiana [sic], was
addedwhen the paper was already in press (Nicolas, 1882: 167, note 1). Because the
paperof Bourguignat results published in May 1882(see frontcover) andthat ofNicolas
on 15July 1882(according to Bourguignat, 1887: 42), Bourguignat's names have pri-
ority over those ofNicolas. However, since Paulia Bourguignat, 1882, is preoccupied
by PauliaGray, 1840(Echinodermata) and PauliaStal, 1869(Hemiptera), Avenionia must
be used as the validname.
As for the specific taxa, Fischer (1885) regarded A. vayssieri asajunior synonym of P.
berenguieri, A.fabri as an uncertainentity based on"un seul individu, enpartie brise, a
une forme generale differente de ses congeneres et pourait meme, d'apres d'auteur,
devenir le type d'un genre particulier", and A.lacordiania [sic] to correspond to P.
lMocardiana. Bouorguignat i(188t7: 42e) regardesd A.fabrsi asajuniioresynonymr(!)ofia
lineolatavar. puteana Coutagne, 1883. Nicolas (1892: fig. 13lris) and Locard (1893: fig.
95) figured a shell of P. berenguieri which looks like that ofa species of Moitessieria.
Germain(1913) was thefirst to propose synonymy ofP. berenguieri andP. locardiana, and
taking the former as the valid name, established the priority ofone ofthe two names
published simultaneously. More recently, Boeters(1967) revised thestatusof these taxa,
illustrated the holotype ofP. locardiana, designated lectotypes of P. berenguieri and A.
vayssieri, confirmed the synonymy ofthese three nominaltaxa and considered P. beren-
guieri as a subspecies ofAvenionia brevis (Draparnaud, 1805). The status ofA.fabri
(amended to A.fabrei by Nicolas, 1892) is still uncertain. Nicolas (1892) stated that
Bourguignat was wrong to claim synonymy withPaladilhia puteana, Germain(1931: 636)
recorded “A. Fabrei Nicolas, 1892, p. 44, fig.13bls" as a synonym ofP.berenguieri, and
Boeters& DeWinter(1983) listed“fabri”,probably insteadof “lacordiana together with
”,
“vayssieri” as a nameused by Nicolas (1882) forA. brevis.
192 BASTERIA, Vol. 64, No. 4-6, 2000
Figs 12-21. Operculumandanatomical detailsofAvenioniabrevis berenguieri(Bourguignat,1882), collectedin
thespringofthefountainofSt. Victor-la-Coste (Gard,France). 12:outersurface (left),profile(centre)andinner
surface (right)ofoperculum;13:bodyofamalewithpallialcavityopentoshow penis; 14:malegenitalia(penis
excluded),stomach, intestine andpallial organs; 15-18:penis in four males; 19: genitaliaandpallial organs
in afemale;20-21: distal portionofgenitaliaintwootherfemales. Abbreviations: AG= albumengland;BC
=bursacopulatrix;C= ctenidium;GG=capsule gland;DSR=distalseminal receptacle(RS1); GO =gonadal
oviduct;GS=glandularswellings;I=intestine;OE=oesophagus;OS=osphradium;OV=ovary;P =penis;
PD = penialduct;PG =prostategland;PL =peniallobe; PSR =proximal seminal receptacle(RS2);PW =
posteriorwallofpallialcavity;R =rectum; RO =renal oviduct;S =stomach;TS=testis;VD=vasdeferens;
VE = vas efferens (seminalvesicle). Scale bar 1 mm.
Bodon et ai:Avenionia redefined 193
DISCUSSION
As is evident from the above description, the type species of Avenionia has a bursa
copulatrix and thegenus istherefore definedby a combinationofanatomicalcharacters
different from that described so farin the literature(bursa copulatrix absent according
to Boeters &De Winter, 1983, and Boeters, 1998). This implies that therelationships
ofthegenus Avenionia and the systematics ofat least some ofthe species includedin it,
need to be revised.
Relationships. - Thecombinationofanatomicalcharacters distinctiveofAvenionia
(males, penis with glandular lobes; females, renal oviduct with two seminalreceptacles
and bursa copulatrix) also occurs in other European genera: Pezzolia Bodon& Giusti,
1986(including the type species Pezzolia radapalladis Bodon& Giusti, 1986,and other
undescribedspecies), Fissuria Boeters, 1981(including only the typespecies Fissuriaboui
Boeters, 1981); LitthabitellaBoeters, 1970(including only the type species Paludinella
(Bythinella) chilodiaWesterlund, 1886) and AlzoniellaGiusti & Bodon, 1984(including
the type species Alzoniella finalina Giusti & Bodon, 1984, and A. sigestra Giusti &
Bodon, 1984; other species assigned to this genus are not included here due to their
uncertain taxonomical position or their separate distribution) (Bodon & Giovannelli,
1993; Bodon et al., 1992, 2000).
Fissuria and Pezzolia can be recognized immediately by their depressed valvatiform
shell, but the distinctionbetweenLitthabitellaand Alzoniella is less evident because both
have a cylindro-conical, bythinelloid shell very similar to that ofAvenionia (by virtue of
a thinand uneflexedperistome, Alzoniella is the more similar). Nevertheless, Avenionia
can be clearly distinguished from all the above generaby the fact that its type species
is definedby the following anatomical characters (table 1):
subapical lobe ofpenis very large, with three glandular swellings along border,
two ofwhich in form of the sinuous bands (subapical glandular lobe absent in type
species ofPezzolia; subapical lobe/ssmall, sessile, glandular in species ofPezzolia, Fissuria
and Alzoniella; subapical lobelarge, non-glandular on apical borderbutwith 1-4 globular
to elongated glandular swellings on lowersurface - and onsurface ofpenis close to base
oflobe - inLitthabitella);
dorsal glandular lobe ofpenis small, globular, on dorsal side of penis close to
baseofsubapical lobe (absent inLitthabitella; absent or, ifpresent,on dorsalside ofpenis
nearbase inPezzolia and Alzoniella; absent or, ifpresent, in variableposition in Fissuria);
proximal seminalreceptacle (RS2) larger than distal and with evident slender
duct (proximal seminalreceptacle smaller than or equal to distal and withoutevident
ductin Pezzolia, Alzoniella,Litthabitella, and Fissuria; sometimeswith shortduct inFissuria);
proximal seminal receptacle (RS2) arising beyond end ofloop, close to distal one
(proximal seminal receptacle arising at end of loop, far from distal one in Pezzolia,
Fissuria, Alzoniella andLitthabitella);
bursacopulatrix very large, in form ofoblong sac, anterior(distal) side ofwhich
adheres closely to posterior (proximal) side ofalbumen gland portion ofpallial oviduct
and posterior (proximal) portion ofwhich extends (towards inside ofvisceral sac) far
beyond site ofproximal seminal receptacle (bursa copulatrix rudimentary or absent in
Pezzolia, small to rather large, always lying onalbumen gland portion of pallialoviduct
and not extending proximally beyond site ofproximal seminal receptacle in Fissuria,
Alzoniella, andLitthabitella);
bursacopulatrix duct short, anteroventral(bursa copulatrix duct rudimentary or
194 BASTERIA, Vol. 64, No. 4-6, 2000
Figs 22-27. Radula ofAvenionia brevisberenguieri(Bourguignat,1882),collected inthe springofthe fountain ofSt.
Victor-la-Coste (Gard,France). 22-23: centralportionofradulawithcentral(C),lateral(L),inner marginal(IM)
andoutermarginal(OM)teeth;24: centralteethshowingonebasalcusp oneach side;25:lateralteeth;26:inner
marginalteeth; 27: outermarginalteeth. Scale bars 10µm (figs 22-23); 5 um (fig. 24); 2 µm(figs 25-27).
absent inPezzolia, short to long in Fissuria, Alzoniella, andLitthabitella, anterodorsalin
Alzoniella and Fissuria, anterior to posteroventral inLitthabitella);
stomach with gastric caecum rudimentary (stomach without gastric caecum in
Pezzolia, Fissuria, Alzoniella, andLitthabitella);
intestineloop onpallial wall absentor poorly defined(well developed pallial loop
in Pezzolia, Fissuria, and Alzoniella, absent inLitthabitella).
Bodon et al.: Avenionia redefined 195
On the basis of the current praxis in the taxonomy of the hydrobiids, Avenionia,
Alzoniella,Fissuria, andPezzolia, havingsuch differentanatomy,maybeconsidereddistinct
validgenera(forPezzolia, seeBodon& Giusti, 1986, and Bodonet al., 2000; forFissuria,
see Boeters, 1981, and Bodon et al., 2000; for Alzoniella, see Giusti & Bodon, 1984,
Bodon, 1988,and Boeters, 1999; forLitthabitella, see Bole, 1971, Radoman, 1983, and
Bodon et al., 1999).
No extra-European taxon shows the same combinationofanatomical characters as
Avenionia. SomegeneraofNorthAmerica, such asNymphophilus Taylor, 1966, Pyrgulopsis
Call & Pilsbry, 1886, and Cincinnatia Pilsbry, 1891, include species whose males have
apenis with glandular swellings in the form ofsinuous bands. Theirfemales, however,
always have only oneseminalreceptacle (Davis & Mazurkiewicz, 1985; Hershler, 1985,
1998; Hershler & Landye, 1988; Hershler & Thompson, 1987).
The speciesofAvenionia.. — In central-westernEurope Avenionia includestwo species,
eachwith two subspecies: A. brevis brevis, distributedfrom theJura to theCote d'Orand
nearby Lyon (France), A. brevis berenguieri, distributedin the Rhonebasin south ofLyon,
inthe French departments ofArdeche, GardandVaucluse(Boeters & DeWinter, 1983);
A. bourguignati bourguignati (Locard, 1883), from the department Aube (France) and A.
bourguignati roberti Boeters, 1967, in the Low Countriesand nearby Germany (Boeters,
1998). All these taxa were first considered to be subspecies ofA. brevis (Boeters, 1967;
Boeters & De Winter, 1983).
Their shell is always cylindro-conical, bythinelloid, and has a thin peristome, not
reflexed and not sinuous at the external margin (Boeters, 1967, 1998; Notenboom &
De Winter, 1983). Anatomicaldatais scarce. Only thepenis ofA. brevis brevisis known,
having awide subapical lobe with glandular, globular and band-likeswellings, and a
dorsalglandular lobevery similar tothosedescribed hereinforA.brevis berenguieri (Boeters
& De Winter, 1983, fig. 2; Boeters, 1998, fig. G 2). A.bourguignati bourguignati and A.
bourguignati robertialsohave apenis witha subapical lobe and glandular swellings (usually
more than two), however neitheris band-like(as in the caseoftwo ofthe swellings in
A. brevis brevis), butglobular to finger-like (Altena, 1946, figs a-b; Boeters & De Winter,
1983, figs 4-9; Boeters, 1998, fig. G 4, 6-7). Female genitalia have only been summarily
figured and described in A. bourguignati roberti and have a very short renal oviduct and
proximal seminal receptacle (RS2) larger than distal (RSI); the bursa copulatrix is
described as absent (Boeters & De Winter, 1983, fig. 1; Boeters, 1998, fig. G 8).
It is clearly impossible to comment on generic and specific taxonomy with such
incomplete anatomicaldata. The fact that they all have a penis with a subapical lobe
andglandular structures, andthat “A. brevis roberti”, the northernmostentity has seminal
receptacles located and shaped like those ofthe type species, supports the hypothesis
that they all belong to Avenionia. Ifthis is true it becomes possible to accept the most
recent opinion ofBoeters (1998) according to which there exist two distinct Avenionia
species, characterized by the different structure ofthe penis: A. brevis (penis having a
subapical lobe with at least two band-like glandular swellings) and A.bourguignati (penis
having a subapical lobe with only globular or finger-like glandular swellings).
The Italiantaxa assigned toAvenionia. Thefact thatAvenioniawas believed to have
female genitalia characterized by a renal oviduct with two seminal receptacles and
withoutbursa copulatrix led to some species from central-northernItaly being assigned
to it (Giusti & Bodon, 1981; Bodon et al. 1995). This was logical because Avenionia
ligustica Giusti & Bodon, 1981 andAvenionia parvula Giusti &Bodon, 1981 (Liguria and
nearby Italianregions) have ashell similarto thatofA.brevis andA.bourguignati (cylindro-
196 BASTERIA, Vol. 64, No. 4-6, 2000
conical, peristome thin, not reflexed and not sinuous at external margin) and a penis
with a glandular subapical lobe (the simpler structure andsmaller size ofthe lobe were
seen as indicating a distinct species) and sometimes (A. ligustica) also with a globular,
glandular lobe onthe dorsal side nearthe base (maybe corresponding to thatsituated
close to the base ofsubapical lobe in A.brevis).
The presentstudy nevertheless revealedthat theseassignments are incorrectwhen the
current practice to distinguish the hydrobiid genera is applied. In fact, apart being
characterizedby a penis whichhas a differentsubapical lobe, A.ligustica andA. parvula,
are now obviously distinguished by the fact that they actually do not have a bursa
copulatrix (there maybe avestigial onein A. ligustica; Giusti & Bodon, 1981, fig. 2 H).
This and the fact that they also differby a proximal seminalreceptacle (RS2) situated
at the end ofthe loop and never larger than the distal receptacle (RSI), a stomach
lacking even rudimentsofthe gastric caecum and the intestineloop well developed on
the pallial wall(Giusti &Bodon, 1981;personal unpublished data),indicate that thetwo
Italianspecies will have tobe includedina generic taxon differentfromAvenionia(Wilke
et al., in preparation).
In northernItaly (Liguria andnearby areas), in sites closetowhere the two supposed
Avenionia species live, at least two species ofthe genusAlzoniella Giusti & Bodon, 1984
(A. finalina Giusti& Bodon, 1984,andA. sigestra Giusti & Bodon, 1984) are alsoknown.
Although Alzoniellafinalina, the type species, has similar male genitalia, it differs from
“Avenionia” ligustica and “Avenionia” parvula by female genitalia with a large bursa cop-
ulatrix and two seminal receptacles, whereas Alzoniella sigestra, has a very small bursa
copulatrix.
All this suggests that all the species in the western part ofnorthern Italy belong to
the samegenus,variablein oneofthecharactersofits femalegenitalia(bursa copulatrix
from rather large to absent), but constant in others such as the location and relative
dimensions ofthe seminal receptacles (the latter characters are rather different from
those ofAvenionia from France; table 1). However, this hypothesis has been disproven
by genetic studies based onDNA sequencing (Thomas Wilke, personal communication,
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aannddttwwoolloonngg,,bbaanndd--lIikkee ggllaanndduullaarrsswweelllliinnggs)oonn
lloowweerrssuurrffaaccee((aannddoonntthhaatt
loolooffbbeepp))eennits*cclolosseelloobbaasseeooff
DDlooobrrassaallggllaanndduullaarr aoeSSsrfiifmmddase*aauullllbboo,,eaffppggppitllcceooeaabnbnlluitua*llaallcoodrr.lbbo,ooOaeasnnaetctdooloobbrnaaaaassllee AgpAgplleebboonasrbbneanuusnnllaatnntrreeoo,,aarroo..rrnnbbiiffaappddssoorreeeerrssasaaeellnnasttiiddaeesmmaooalffl.l ApAgpgellbbeoonssbnbieesuusnnllaattnnrrooee,rraaoo,,rrnnbbiiffaaddppssoorreeerressssaaeellnntsst,iiddsseemmaaoollffll AAbbaseanntt AoAossmmrrbbasaallaaellall,,ttnneettrrggaaoolllloorrbba,,suuiiddiillffaaaepprr,,rrooaeffooasppenaneennnnddtt,ii,oossrrssIinaanll AgpAgpeellbboonasrbbneiesuu*nmlltnnaaeerroo,,aarroo,.rrnniibbffaappddasrrooeeearrsssseaaenllntsst,iiddsseemmaaoolllltf..
vvaarriiaabbMleppoosaittlioonn
F*em*ale rPPercrwoedxpimmtaeacllleseeemmininaali LLWWaairatrghgfteerasrlleetthhnnaaddnneerrddiiddssuuttaaddll WVSSVmmitthhaaoolalueuetrtrtetehhvvaaiiddnneennddttiiasttddaauulldd WWSSmmiitthhaaooaauueettrrtetehhvvaaiiddnneennddttiiastt3daauullcdt WWSSmmiittahhaMoolleuuerttrtetehhvvaaiiddnneennddttooddttaauullcdt NNWWooiitttthholloaauurrtggteeoorrrrtwtwhhiiaatthhnndsdshhiiasoottarrattlldduuedl NNWWooiitttthhllooaauurrggtteeeerrvvttiihhddaaeennnnttddddiiasuuttaddall
BBeeyyoonnddtlhiteeeennddoofftthrieelloooopp AAtttthheeeennddoofftthheelloooopp AAtttthheeeennddoofftthheelloooopp AAtttthheeeennddoofftthheelloooopp AAtttthheeaennddoofftthheelloooopp AAtttthheeeannddoofftthheelloooopp
BBuurrssaaccooppuuflaattrrtixi VVearryywwKitdea SSmmaallttoowwtrddee AAsbsseenntt WWiUdee SSmmaelliitolowwWidee RRuuddlimmeennttssl!oorraabbaseanntt
Beyondabumengland LLyyiinnggoonnaaJlbbuummeennggllaanndd U{Innaappppflciccaabbltee)) LLyyiinnggoonnaablbuummeennggllaanndd LLyyiinnggoonnaafbcuummeennggllaanndd LLyyiinnggoonnaalrbbuummeennggllaanndd
PPrroottrruuddiinnggppoosetteerrioiorrlyty NNoottpprroottrruuddirintggppooastteernioorrltyy (ilInnaappppfclcicaaWbele}) NNoottpprroottrruuddiinnggppooasttearriioorrltyy NNoottpprroottrruuddiinnggppoosatteerriotorlryty NNoottpprroetlruuddimnggppoosstteerriioorrllyy
BBuurrssaalldduucctt SShhoorrtt SShnoorrtttloommeoddi-uumrn ((IInnaapppplsiccaabblete)) MMeeddiiuumm SShhoorrttttoolloonngg RRuuddiimmeennttaallootraabbsseenntt
AAnnttaerroavveentnntMral AArrrrttaerrooddoorrssaall (iIInnaappppliiccaabbllee;) AAnntteerriioorrttooppooasMterroovveennttrrsaIl AArnrtteerrooddoornsaell ((Iinnaapppplaiccaabblaef))
SSttoommaacchh G0a—sttrriiceccaaeeccuumm RRuuddiimmeenntat*l AAbbaseanntt AAbbaseanntt AAbbaseanntt AAbbaseanntt AAbbsseenntt
I•nnteteobrnta*. PPaaWWaelllolooopp AAbbsaeannttoorrrruuddramnaenrttaaii WVVeeilddeevveellooppeedd WWeeiltddeevveellooppeedd AAbbaseanntt WWeellllddeevveelolopepded WWeel*lddeevveeloloppeedd
Table 1. Comparison ofthe various generadiscussed inthe present paper.