Central Tyrrhenian sea Mollusca: XI. Description of Callostracon tyrrhenicum sp. nov. (Gastropoda, Acteonidae) and remarks on the other Mediterranean species of the family Acteonidae d’Orbigny, 1835

11 Pages·1996·2.1 MB·English

by  Smriglio, Carlo

BASTERIA, 60: 183-193, 1996
Central Tyrrhenian sea Mollusca: XI.
Description ofCallostracon tyrrhenicum sp. nov.
(Gastropoda, Acteonidae) and remarks onthe other Mediterranean
species of the family Acteonidae d’Orbigny, 1835
Carlo Smriglio
Via di Valle Aurelia 134, 1-00167 Rome, Italy
& Paolo Mariottini
DipartimentodiBiologia,Terza Universita degliStudi diRoma,Via Ostiense 173, 1-00154 Rome,Italy
Anewacteonidspecies, collectedintheCentral TyrrhenianSea,ishere described. Itisplaced
inCallostracon Hamlin,1884,andnamedC.tyrrhenicum.Thedescriptionisbasedonshellmorpho-
logyonly.Remarkson the fourbathyalandthethreeinfralittoral speciesofthefamilyActeonidae
known from theMediterranean Sea, arealso featured.
Key-words:Gastropoda,Opisthobranchia,Acteonidae, Callostracon,taxonomy, bathyalfauna,
Central TyrrhenianSea, Italy.
INTRODUCTION
In the framework ofan investigation carried out over the past decade, we continue
to characterize the bathyal faunalassemblages from the Central Tyrrhenian Sea, off
the Latialcoast (Italy) (Smriglio et al., 1987, 1990, 1992, 1993). In particular, we are
interested in the molluscan fauna occurring in the deep-sea coral (biocoenose des
coraux blancs, CB) and muddy-bathyal (biocoenose des vases bathyales, VB) commu-
nities (Peres & Picard, 1964) of this area. In this paper we describe a new species of
acteonid,Callostracon tyrrhenicum, from materialdredged in a deep-sea coralbankoffthe
Latial coast. Among the molluscan faunaassociatedwith C. tyrrhenicum, we have iden-
tified four bathyal acteonids, which we think worth reporting: Acteon monterosatoi
Dautzenberg, 1889, Crenilabiumexile (Jeffreys, 1870, ex Forbes ms.), Japonacteon pusillus
(McGillavray, 1843), and Liocarenus globulinus (Forbes, 1844). In order to present a
comprehensive picture ofall the Mediterraneanspecies ofthis family, we give some
dataon the remaining three infralittoralacteonids: Acteon tornatilis (Linne, 1758), Pupa
candidula (Monterosato, 1923) and Bullinopersilia sphaeroides F. Nordsieck, 1972.
MATERIAL
The new taxon and the four bathyal acteonids reported have been identifiedfrom
an analysis ofabout 90 kg ofmarinesedimentdredged at a depth of360-600 mfrom
theCentral Tyrrhenian Sea (coast ofLatium, 41°51'N11°28'E, 41°24'N12°3'E). Unless
stated otherwise, all specimens are stored in the authors'collections. The type material
184 BASTERIA, Vol. 60, No. 4-6, 1996
of P. candidulabelonging to the Monterosatocollection deposited in the Museo Civico
di Zoologia di Roma (MCZR) has been studied. A specimen of Acteon tornatilis luteo-
fasciatus (Muhlfeldt, 1829) belonging tothe private collectionofDr.C. Ciommei(Rome)
has been examined.
THE NEW TAXON
Callostracon tyrrhenicum sp. nov. (figs. 1a-6)
General description ofthe shell. — Shell small, ovate-conical, cylindrical with the
upperpart slender (figs, la-b, 2b-5). Protoconch heterostrophic, submerged and semi-
globose, consisting ofa larval shellwith non-planktotrophic development ofaboutone
and ahalfexternal whorl (fig. lc). There are five convex teleoconch whorls, showing
a microsculpture consisting of spiral striae. Strong magnification reveals that these
striae are indeed shallow ovoid depressions, chain-like, close to each other and equi-
distant (fig. Id). The suture is well impressed. Peristome straight and sub-romboid,
narrower in the upperpart. Columellastraight with a little fold in the middle; outer
lip crenulated. The aperture measures about 0.5 ofthe total height. Colour whitish
hyaline. Operculum and soft parts unknown.
Derivatio nominis. — The specific name tyrrhenicum refers to the area ofthe Med-
iterranean where the type material has been collected.
Locus typicus. — Central Tyrrhenian Sea off the Latial coast (41°41'N11°28'E).
Habitat. — Biocoenosis CB (biocoenose des coraux blancs; Peres & Picard, 1964)
Type material.— The holotype is 3.4 mmlong (H) and 2.0 mm wide (D), the ratio
H/D is 1.7; paratype Ais 3.4mm (H) and 2.1 mm (D), theratio H/D is 1.6; paratype
B is 3.0 mm (H) and 1.8 mm (D), the ratio H/D is 1.7; paratype C is 3.4 mm (H)
and 2.2 mm (D), the ratio H/D is 1.5; paratype D is 1.5 mm (H) and 1.1 mm (D),
the ratio H/D is 1.9.
The holotype is stored in the Laboratorio di Malacologia, Universita di Bologna
(MZB no. 11624, Italy). Paratypes A, B, C andD are kept in the authors' collections.
Discussion. - Individuals ofthis new taxon have been reported twice in the past
from the Mediterranean Sea (Cecalupo & Giusti, 1986, 1989); all specimens were
dredged at a depth of400-600 m in the Tuscan Archipelago (south-west ofCapraia
Island, Italy). In both casesthe acteonid shells were tentatively referred to Callostracon
cf. amabilis(Watson, 1886). Sabelliet al. (1990, 1992) quoted this species among the
mediterraneanacteonids, but s.n. Ovulacteon cf. amabilis (Watson. 1886), without com-
menting onthe different genus collocation. C. amabilis is an Eastern Atlantic species
which differs from C. tyrrhenicum in its general shell morphology and sculpture. In
particular, in C. amabilis the last whorl is clearly carinate, the columellarfold is posi-
tioned at the beginning ofthe columellaand the microsculpture has a smaller number
ofspiral striae. The distributionof C. amabilis seems to be limitedto an oceanic area
spanning the Western Azores, Madeira and the Canary Islands (Nordsieck, 1972).
Illustration(fig. 6) and detailed description ofthe shell of C. amabilis are in Thomson
& Murray (1886). We thinkthatthe two previous records ofC. cf. amabilisin Cecalupo
& Giusti (1986, 1989) areboth incorrect identifications, because thefigured individuals
are C. tyrrhenicum. On the other hand, we keep the newly proposed taxon in the genus
Callostracon Hamlin, 1884, since the features of the protoconch and the teleoconch
(shape, sculpture, size) agree well with such a classification.
Smriglio & Mariottini:Callostracon tyrrhenicum sp. Nov. (Acteonidae) 185
Figs. 1-6.Shells of Callostracon. 1a-5. Callostracon tyrrhenicumsp. nov. 1a-b,apertural and dorsalviews ofthe
holotype,MZBno. 11624(Bologna,Italy),3.4x2.0mm; 1c,protoconchoftheholotype;1d,detailoftheshell
surface showingthepeculiarsculpture;2a-b,aperturalanddorsal viewsofparatype A,3.4 mm x 2.1mm;3a-
b,aperturalanddorsal viewsofparatype B, 3.0mmx 1.8mm;4a-b,aperturalanddorsalviews ofparatypeC,
3.4mmx2.2mm;5,aperturalviewofparatype D, 1.5mmx 1.1mm.6.Callostraconamabilis(Watson, 1886).Type
figureafterThomson&Murray(1886).Allspecimensfiguredinfigs. 1-5arefromtheCentral TyrrhenianSea
(41°41’N11°28’E),allparatypes arekeptinthe authors’collections.
186 BASTERIA, Vol. 60, Mo. 4-6, 1996
Figs. 7a-12b. Shells ofMediterranean bathyalacteonids and apulmonategastropod. 7a-b,Acteon monterosatoi
Dautzenberg, 1889,aperturaland dorsalviews,3.6 x 2.1mm. 8a-9b,Crenilabiumexile(Jeffreys, 1870exForbes
ms.);8a-b,aperturalanddorsalviews,4.2x 1.8mm;9a-b,aperturalviewofajuvenilespecimen,2.0x 1.1mm.
10a-b, Cecilioides acicula (Müller, 1774),apertural and dorsal views, 4.5 x 1.4 mm. 11a-b, Japonacteonpusillus
(McGillivray,1843),aperturalanddorsalviews,6.5x3.4mm. 12a-b,Liocarenusglobulinus(Forbes,1844),apertural
anddorsal views,3.4x2.3mm. AllspecimensfiguredarefromtheCentralTyrrhenianSea,(41°41’N11°28’E),
andarekept inthe authors’ collections.
Smriglio & Mariottini:Callostracon tyrrhenicum sp. not: (Acteonidae) 187
THE MEDITERRANEAN BATHYAL ACTEONIDS
Acteon monterosatoi Dautzenberg, 1889 (figs. 7a-b)
Morethan200 specimens, lacking softpartsbut very fresh, ofthis species have been
sorted out. A. monterosatoihas been already recorded fromthe CentralTyrrhenian Sea
(Oliverio & Villa, 1981) with the finding offive individuals.
Crenilabiumexile (Jeffreys, 1870 ex Forbes ms.) (figs. 8a-9b)
About 30 specimens, lacking softpartsbutvery freshandrepresenting adult, subadult
and juvenile shells, of C. exilehave been screened. This species was already recorded
from the Central Tyrrhenian Sea, coast ofLatiumby Oliverio & Villa (1981). Fasulo
et al. (1982) pointed out that the presence ofspiral striae on the shell surface ofthis
species was a contradictorymatter,not solvedby theauthors whoreported C. exilefrom
the MediterraneanSea in the past. The individualsexamined show indeedthis kind
offine sculpture, which is also presentin theyoung specimens. The only figure found
in the literatureshowing a specimen ofC. exilewithoutsculpture isby Nordsieck(1972);
in fact, he mentions a smooth shell surface without spiral striae: "Mit sehr obsoleten
spiralen". The figure in his work is referred to Cecilioides acicula (O. F. Miiller, 1774),
a European pulmonate gastropod (Kerney & Cameron, 1979). Finding thisspecies, and
other land and also freshwater shells, in material dredged even at a very great depth
(Gaglini, 1981) is anot altogether rare event. This sortofcontaminationis due to the
well-known resedimentationprocesses fromthe shelfdownto the basin (Bonfitto et ah,
1994).To support our interpretation, duringtheanalysis ofa marinesediment dredged
in the sameareaofthe CentralTyrrhenian Sea at a depthof450 m,we have identified
several individualsofC. acicula(figs. 1Oa-b). Itmustbementionedthatthe general shape
ofthispulmonate gastropod strongly resembles thatof C. exile, whichis the reasonwhy
some erroneous records ofthis acteonidoccurred in thepast (Nordsieck, 1972; Tene-
kidis, 1989; Arduino et al., 1995).
Japonacteon pusillus (McGillivray, 1843) (figs. 11a-b)
Fifteen specimens, lacking soft parts, of this species have been identifiedscreening
a marine sediment from the muddy bathyal bottoms surrounding the coral banks
investigated. J. pusillus seems to occur in a wide bathymetric range, from the deep
circalittoralto the bathyal, butalways in muddy andmuddy-detritic bottoms (Terreni,
1981; Fasuloet ah, 1982). A recordofan individualofthis species collected at a very
low depth (24-49 m) from Flaifa (Israel), has been given by Barash & Danin (1992).
This peculiar finding can be interpreted as anaccidental import to shallow water by
fishermenoperating in thatarea. OurreportofJ. pusillus is thefirstonefrom theLatial
coast.
Liocarenus globulinus (Forbes, 1844) (figs. 12a-b)
Six individuals, lackingsoftpartsbutratherfresh, ofL. globulinushave beenidentified
in the dredged material. The outer surface ofthe teleoconchshows a fine sculpture
consisting ofspiral striae, which, under strong magnification, appear as dotted lines.
ThedistributionofL. globulinus rangesfrom theEasternAtlantic Ocean(Lusitanic area)
188 BASTERIA, Vol. 60, No. 4-6, 1996
Figs. 13-16.ShellsofActeonandPseudoacteon. 13a-15b.Acteon tornatilis(Linné, 1758). 13a-b,aperturalanddorsal
views, 9.8 x4.0mm, Civitavecchia (RM),CentralTyrrhenianSea,-22 m; 14a-b,aperturalanddorsal views,
10.2x 6.0mm, Hornaijarfarmia,Atlantic Ocean,collectedashore; 15a-b,aperturaland dorsal views, colln.
Ciommei(Rome,Italy),2.2 x 1.2mm,Civitanova Marche(MC), Central AdriaticSea,-40m. 16.Pseudoacteon
luteofasciatus(Mühlfeldt,1829),typefigureafterNordsieck(1972).Unlessstatedotherwise,thespecimensfigured
are storedintheauthors’ collections.
Smriglio & Mariottini: Callostracon tyrrhenicum sp. Nov. (Acteonidae) 189
to theMediterraneanSea (Aegean Sea) (Fasulo et al., 1982;Koutsoubas &Koukouras,
1993). This is the first record of L. globulinus from the Latial coast.
THE MEDITERRANEAN INFRALITTORAL ACTEONIDS
Acteon tornatilis(Linné, 1758) (figs. 13a, 15b)
This species is commonly occurring on the infralittoralsandy-muddy bottoms ofthe
MediterraneanSea (Terreni, 1981); in spite of a relatively simple shell form and
sculpture, A. tornatilisshows alot ofintraspecific polymorphism. Shell length up to 25
mm,elongate, cylindrical, solid, uniformelylight pinkish; butsome shellsshowtwo pale
spiral bands edged by dark brown lines. The teleoconch exterior surface has a fine
sculpture consisting ofmany spiral striaewhich canextend throughout the entireshell,
but generally are more evident at the base of the last whorl. This species can be
commonly collected on the shore after storms; a good percentageofthe specimens is
generally already deadandthe shellsare utilizedby hermitcrabs(Crustacea Decapoda,
Paguridea). For this reason, manyofthe individualsexaminedare pale (bleached) little
sculptured or almost smooth because ofthe prolonged abrasion on the sand. This
colourandsculpture variation(figs. 13a-14b), due to both genetic factors and sampling
conditions, has lead some authors in the past to create many forms of A. tornatilisor
even distinct taxa whose validity is still doubtful. For instance, Nordsieck (1972) has
reported Pseudoacteon luteofasciatus (Miihlfeldt, 1829) fromthe AdriaticSea(Rimini, Italy)
as a validtaxon (fig. 16). Fasuloetal. (1982) already consideredita simple colourform
of A. tornatilis. We havefigured a youngindividualofA. tornatiliswhich represents this
colour form and was also collected in the Adriatic Sea (figs. 15a-b); we agree with
Fasulo et al. (1982) in considering it as a peculiar variantofthe colourpattern shown
by this species, maybe typical of the Mediterranean Sea. We propose Pseudoacteon
luteofasciatus (Miihlfeldt, 1829) as a synonym of Acteon tornatilis (Linne, 1758).
Pupa candidula (Monterosato, 1923) (figs. 17a-18b)
Theoriginal description ofP. candidulaby Monterosato(1923), referring to only three
individualsfrom the coast of Cyrenaica (Libya), is: "A. candidulus, Monts. nov. sp. —
Tre soli esemplari, dei quali unointero. E' una forma piu piccola del conosciuto A.
tornatilis,interamenteCandida, solida, comeunaspecie delgenereSolidula, che manca
da noi. Lasuperficie eben levigata con poche strie spirali aliabase". Nordsieck (1972)
reported this species but surprisingly changing its genus to Pupa Roding, 1798. This
genus has as a peculiar diagnostic feature consisting oftwo strongcolumellarfolds on
the inner lip, which are not present in the genus Acteon Montfort, 1810. Nordsieck
(1972: 9) gives a short description ofP. candidula, which is definedas avery solid shell,
totally white, 10-15mm inheight, almostsmooth with spiral striae present only at the
base of the last whorl: "Sehr fest und ganz weiss. Glatt und nur mit basisspiralen".
Unexpectedly Nordsieck does not mention the two columellar plicae. Fasulo et al.
(1982) commenting on P. candidula in theirpaper, add to the description ofthe shell
this very important diagnostic character: "Doppia denticolazionealia base dellacolu-
mella". To solve this taxonomic controversy, we examinedthe type materialof P.
candidulakept in the Monterosatocollection(MCZR). Underno. 16053we found only
two specimens (figs. 17a-18b), together with the original labels in the handwriting of
190 BASTERIA, Vol. 60, No. 4-6, 1996
Figs. 17-23.ShellsofPupaActeonandBullinopersilia.17a-18b.Pupacandidula(Monterosato,1923),colln.Monterosato
MCZR no. 16053(Rome,Italy). 17a-b,apertural and dorsalviews, 8.0x 4.0mm; 18a-b,aperturalanddorsal
views,8.8 x4.8mm; 19a-20.originallabelsin Monterosato’s handwritingreferringtospecimensoffigs. 17a-
18b.21a-b.Acteontornatilis (Linné,1758),aperturalanddorsalviews, 12.0x7.0mm,SanTeodoro(SS),Eastern
Sardinian Sea,collectedashore.22a-b.Pupacf.solidula (Linné,1758),aperturalanddorsalviews, 17.0x8.2mm,
SouthMolle Island,SouthAustralia,collectedashore.23.BullinopersiliasphaeroidesNordsieckF., 1972,typefigure
after Nordsieck(1972). Unless statedotherwise,thespecimensfiguredare storedintheauthors’ collections.
Smriglio & Mariottini: Callostracon tyrrhenicum sp. Nov. (Acteonidae) 191
Monterosato (figs. 19a-20). The smaller individual fits perfectly with the original de-
scription published by Monterosato (1923), but it does not show the two columellar
folds! We do not understandthe reason why it has been moved from Acteon to Pupa,
because of the lack of such an important diagnostic feature. Moreover, a careful
examination ofthe type material revealed the presence of spiral striae on the shell
surface. Morestrikingly, notwithstanding thegeneral pale whitecolourofthe shell, the
bigger and incomplete individualshows the typical pattern consisting oftwo lighter
bands which commonly occurs in A. tornatilis (figs. 18a-b). We think that these two
specimens were probably collectedashore, whichcouldbe thereason oftheirpale colour
andsmoothness. During theanalysis ofmany specimens ofA. tornatiliswefound several
cases ofshells presenting the samefeatures; oneofthese cases isfigured as an example
(figs. 21a-b). Probably Monterosatoignored the incomplete specimen when describing
P. candidula, but in this case broken does not mean less important! As anexample of
a shell belonging to the genus Pupa Roding, 1798,we figured Pupa cf. solidula(Linne,
1758) (figs. 22a-b). We propose Pupa candidula (Monterosato, 1923) as a synonym of
Acteon tornatilis (Linne, 1758).
Bullinopersilia sphaeroides F. Nordsieck, 1972 (fig. 23)
The species andthegenuswere proposed by Nordsieck(1972: 8)ona single specimen
collected in thelittoralbottoms ofIbiza (Balearic Islands, Spain). The original descrip-
tions ofthe genusandspecies is: "Bullinopersilia nov. gen. Typus: sphaeroides n. sp.
Oval mit stumpfer Spira und schlanker Basis. Glatt, nur mit wenigen Anwachsrissen.
Letzter Umgang sehr gross, Mundung sehr hoch, fast gleichbreit. Lippe scharf. Spindel
geknickt, unterer Teilkallos undsteil, mit einer schwachenoberen Drehfalteund einer
starkeren unteren Stutzfalte, darunter ausgussartig ausgeschnitten. Zwischen Persilia
und Bullina stehend.
Bullinopersilia sphaeroides n. sp. - 2,5/1,5 mm. O I 4, Typus von Ibiza. - Ibiza,
Sublitoral.Form eines aufder Spitze stehendenEies mit aufgesetzter stumpfer Spira.
Beidseitig gleichmassig gerundet, globulos. Ziemlich fest, opak bis semitransparent,
blass weissrosa. Apex flachkuppelformig abgestumpft. 3Vi Umgange, flachkonvex, mit
flacher Naht. Letzter Umgang= 7/8 derHohe. Miindung etwa 4/5 der Hohe. Schale
glatt, bis auf feine Anwachsfaltchen an der Naht. Letzter Umgang nach unten ver-
schmalert, Miindungsrand desgleichen. Miindunglanggestreckt, obenetwasverschmalert.
Spindel steil, kallos, miteiner schwachenoberenDrehfalteund einerstarkeren unteren
Stutzfalte, darunter ausgussartig ausgeschnitten".
The iconography accompanying the description of this taxon raises strong doubts
about the validity ofit (fig. 23). We could not examine the type materialkept in the
collection of the Senckenberg Museum of Frankfurt am Main (SMF), but Dr. R.
Janssen has kindly communicatedus (in litt., 23.01.1996) that the type material is
indeed a juvenile ofthe land snail Ferussaciafolliculus (Gmelin, 1791), a Mediterranean
pulmonate species (Cossignani & Gossignani, 1995), mainly occuring in Catalonia
(Spain) (Haas, 1991). This is another caseofa terrestrial shell collected in the sea by
the above mentionedresedimentationprocesses (Bonfitto et al., 1994). We propose
Bullinopersilia sphaeroides Nordsieck F., 1972as a synonymofFerrussaciafolliculus (Gmelin,
1791).
192 BASTERIA, Vol. 60, No. 4-6, 1996
ACKNOWLEDGEMENTS
We would like to express our gratitude to Dr. Philippe Bouchet (Museum National
d'HistoireNaturelle, Paris, France) forhis criticalcomments and advice onthepresent
paper. We are really grateful to Dr. RonaldJanssen (Senckenberg MuseumofFrank-
furt, Germany) forcorrespondence concerning thetaxonomic problem ofB.sphaeroides.
We are very indebtedto Dr. Vincenzo Vomero (Museo Civico di Zoologia di Roma,
Italy) for the examinationofthe type materialof P. candidula. Sincere thanks are due
to Dr. Antonio Bonfitto (Museo di Zoologia dell'Universita di Bologna, Italy) for
generously providing references. We furthermore thank Dr. Alessandro Hallgass and
Mr. Carlo Cavalieri for their cooperation in supplying literature; Dr. Gesare Ciommei
for the loanofmaterialfrom its collection; Miss SimonaPellis for helpful translation
ofNordsieck's paper; Mr. Walter Cipriani for kindly supplying Australianmalacolo-
gical material; Mr. GiannandreaBulgarini for technicalassistance.
REFERENCES
ARDUINO,G.,B.LOCATELLI,F.ORLANDO&G.REPETTO, 1995.Catalogoillustrato delle conchiglie
marine del Mediterraneo: 1-197.Alba (CN).
BARASH,A.,& Z.DANIN, 1992. Fauna Palestina,Mollusca 1 - AnnotatedlistofMediterraneanmolluscs
ofIsrael and Sinai: 1-405.Jerusalem.
BONFITTO,A.,M.BIGAZZI,I.FELLEGARA,R.IMPICCINI,S.GOFAS,M.OLIVERIO,M.TAVIANI
&N.TAVIANI,1994.Rapportoscientificosullacrociera DP'91 (margineorientale dellaSardegna,Mar
Mediterraneo).— Boll. Malac. 30: 129-140.
CECALUPO, A.,&F. GIUSTI, 1986. Rinvenimenti malacologiciaSud Ovestdell'Isola diCapraia(LI).—
Boll. Malac.22: 293-298.
-& , 1989.RinvenimentimalacologiciaSud Ovestdell'IsoladiCapraia(LI)ParteII.—Boll. Malac.
25: 97-109.
COSSIGNANI, T.,&V.COSSIGNANI, 1995.Adantedelleconchiglieterrestri edulciacquicoleitaliane: 1-
208. Ancona.
FASULO, G.,F.IZZILLO& E.PERNA, 1982. Malacofauna vivente nel Golfo diNapoli,parte 3.Famiglia
ACTEONIDAE.— La Conchiglia14:6-11.
GAGLINI,A., 1981.MelanellididelMediterraneo: igeneriStrombiformiseHaliellainparticolare.— Notiziario
C.I.S.MA. 3:45-54.
HAAS,F., 1991. Faunamalacologicaterrestreydeaguadulce deCataluna. —Treb.Mus.Zool. Barcelona 5
1-491.
KERNEY,M.P.,&R.A.D.CAMERON, 1979.AfieldguidetothelandsnailsofBritainandNorth-WestEurope:
1-288. London.
KOUTSOUBAS, D.,&A.KOUKOURAS, 1993.An accountofourknowledgeontheOpisthobranchmollusc
faunaoftheAegeanSea. —Boll.Malac. 29: 191-200.
MONTEROSATO, T. A.DI, 1923. MolluschidellecosteCirenaiche raccolti dall'Ing.Camillo Crema. —
Comit. Talassogr.Ital.Mem.Venezia 107: 1-23.
THOMPSON,C.W.,&J.MURRAY,1886.ReportonthescientificresultsofthevoyageofH.M.S.Challenger
duringthe years 1873-1876. Zoology, Reportonthe Gasteropoda,XV.:1-756. London.
NORDSIECK, F., 1972.DieeuropaischenMeeresschnecken. (OpisthobranchiamitPyramidellidae,Rissoacea)
VomEismeerbisKapverden,MittelmeerundSchwarzes Meer:I-XIII, 1-327.Stuttgart.
OLIVERIO,M.,&R.VILLA,1981.Contributo aliaconoscenza deiMolluschiconchiferi deifondalisublitorali
laziali: I)reperti deipescherecci diFiumicino. —Notiziario C.I.S.MA. 3:33-44.