Table Of ContentGarcia Cirsotrema benettorum n.sp. Novapex 1 (3-4) : 105-107, 20 oct. 2000
Description of a very distinct Cirsotrema (Gastropoda: Epitoniidae)
from New Caledonia.
Emilio F. GARCIA
115 0akCrestDr.
Lafayette, LA 70503
USA
KEYWORDS. Gastropoda, Prosobranchia, Epitoniidae, Cirsotrema, taxonomy, New Caledonia.
ABSTRACT. A new gastropod species fromNew Caledonia assigned tothe family Epitoniidae,
genus Cirsotrema, is described.
INTRODUCTION whorl as wide as it ishigh , height slightly more than
half of lengh of shell (see Table 1), with a heavy
A few years ago came into my possesion three basai cordthat fuses withbase ofhp, creating a wide
spécimens of a very distinct epitoniid species that lobe. Aperture round, peristome continuous, thick,
had been dredged off New Caledonia. After with a slightly free, thinner edge at posterior portion
unsuccessful attempts at identification, and in of inner lip. Varices appear from antepenultimate
consultation with well known students of the whorl onward; randomly arranged, increasing in
Epitoniidae, I sent a preliminary description and thickness and number, from 1 to 6 in the penultimate
photographs to Dr. Philippe Bouchet at the Muséum whorl to 4 to 9 in the last, some varices formed by
National d'Histoire Naturelle, Paris, France. Dr. fusion oflast two ribs; thick, slightly reflected, with
Bouchet located, and kindly sent to me for study, prominent spine at shoulder. Shell sculpture with
spécimens ofthe same taxon collected in deep water narrow, reflected axial ribs between varices, not
in dredging expéditions around New Caledonia from necessarily aligned from whorl to whorl, on each
September. 1985 to August, 1994. The new taxon is whorl terminating above the suture, and at basai cord
describedherein. on last whorl; number of ribs variable, 15 to 33
(excluding varices) on penultimate whorl, with
Abbreviations ofrepository institutions shoulder spine where not broken. Intervais between
ribs with numerous, poorly defmed spiral cords that
MNHN- Muséum national d'Histoire naturelle, Paris, tend to go up the ribs abaperturally. Operculum
France black, paucispiral, round.
SBMNH- Santa Barbara Muséum ofNatural History,
Santa Barbara, California, U.S.A. Type material.
SYSTEMATICS Holotype (MNHN) lenght 31.4 mm, width 16 mm.
Dredged alive offnorthern New Caledonia, 19°04' S,
Superfamily EPITONIOIDEA 163°27' E, in 264-270 m. Paratype A (SBMNH)
Family EPITONIIDAE S. S. Beny, 1910 length 23.3 mm, width 13 mm. Paratype B (MNHN)
Genus Cirsotrema Môrch, 1852 lenght 24.7 mm, width 13.5 mm. Paratype C
(MNHN) lenght 24.7 mm, width 13.5 mm. Paratypes
Cirsotrema (Cirsotrema) benettorum, n. sp. A-C were dredged dead offsouthern New Caledonia
Figs 1-5 in 255-445 m. Paratype D (MNHN) lenght 4 mm,
width 2 mm. Dredged dead at 19° 04' S, 163°27' E, in
Description. 260 m. Four other live-collected spécimens from the
same lot as the holotype are herewith designated as
Shell turbinate, thick, white; length to 33.2 mm. unfigured paratypes (MNHN). Another paratype
Protoconch white, smooth, thin, translucent, of two dredged offsouthern New Caledonia in 310-325 m is
whorls; fïrst whorl minute, second whorl much inthe author's collection (# 22564).
larger, bulbous, offset from first teleoconch whorl
(fig. 5a); teleoconch whorls 11.5 to 12.5 , first 4 very Type locality.
small, fragile and easily eroded, next whorls rapidly
enlarging (fig. 5b); early whorls convex, later whorls Off northern New Caledonia, at 19o04'S 163°27'E,
shouldered; suture moderately deep, crossed by axial dredged in 264-270m.
ribs, some ribs adhering toribs ofearlierwhorl.
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Garcia Cirsotrema benettorum n.sp. NOVAPEX 1 (3-4) : 105-107, 20 oct. 2000
Distribution Because ofthe uniqueness ofthe shell characteristics
of the species we hâve not attempted to compare it
Spécimens examinée! were collected between 18°17' with other taxa. Cirsotrema bennettorum seems to be
S 163°25'E and 23°44'S 168°16'E, at depths from 255 a rather conservative species in its turbinate shape;
m
to 445 m. however, it is extremely variable in the number of
varices and ribs (see Table 1). This characteristic
Etymology. supports DuShane (1974: 4) in her assesment that the
Named in honor of Jo and Rusty Bennett, of Fort hmits of spécifie variation in the number of ribs
Myers, Flonda, for their four décades ofdévotion to are greater in those species havmg more ribs. Extra
the study ofseashells. large ribs begin to develop on sixth teleoconch whorl
(Fig.5b). Thèse ribs, because oftheir width, look like
Discussion. varices when seen laterally; however, they are
structurally thin and are not considered herewith as
The supraspecific placement of members of the true varices.
Epitoniidae is not an easy matter (see Bouchet and The fragility and small size of the first four
Warén, 1986: 469-479), and the Sthenorytis-\\ke teleoconch whorls makes them vulnérable to
shape and the heavy and numerous varices of the breakage and érosion, and ail 26 adult spécimens
shell ofthe new species hâve not made this task any examined hâve lost them; equally, the spme
easier. However, the spirally sculptured shell and formation at the shoulder of the ribs are easily
thick basai cord places it closest to Cirsotrema. eroded.
HOLOTYPE PARATYPE A PARATYPE B PARATYPE C
mm mm mm mm
Length ofshell 31.4 23.3 24.7 24.7
mm mm mm mm
Width ofshell(including varices) 16 13.0 13.5 13.5
L/W ratio ofshell 1.91 1.79 1.83 1.83 mm
mm mm mm mm
Height oflast whorl 16 13.0 13.5 13.5
mm mm mm mm
Width oflast whorl 16 13.0 13.5 13.5
H/W ration oflast whorl 1.0 1.0 1.0 1.0
Numberofvarices inpenultimate 4 5 4 6
whorl
Numberofvarices in last whorl 9 8 7 7
Number ofribs inpenultimate 30 19 26 22
whorl(including varices)
TABLE I : Chart showing relevant dimensions andcharacteristics ofthe four figured adult type spécimens of
Cirsotrema bennettorum
ACKNOWLEDGEMENTS: My thanks to Mrs. Références.
Helen DuShane for her advice and for reading the
manuscript, and to Dr. R. N. Kilburn for his Bouchet, P., & Warén, A. 1986. Revision ofthe
comments on the new species. I also would like to NortheastAtlantic bathyal andabyssal Aclididae,
thank Mr. Roland Houart, who gave very valuable Eulimidae, Epitoniidae (Mollusca, Gastropoda).-
suggestions, Dr. Philippe Bouchet and the Muséum Boll. Malac. Supplément2: 299-576.
National d'Histoire Naturelle for the loan ofessential
matenal and documentation, and Dr. Suzanne DuShane, H. 1974. The Panarnic- Galapagan
Fredencq, of the University of Louisiana at Epitoniidae. The Veliger 16 Supplément: 1-84.
Lafayette, whose help was essential in the production
ofthe plate.
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Garcia Cirsotrema benettorum n.sp. NOVAPEX 1 (3-4) : 105-107, 20 oct. 2000
Figs. 1-5 Cirsotrema bennettorum n. sp.
la-b. Ventral and dorsal views ofholotype (Length: 31.4 mm; width: 16 mm). 2a-b. Dorsal and ventral views of
paratype A (Lenght: 23.3 mm; width:13.0 mm). 3a-b. Dorsal andventral views ofparatype B (Lenght: 24.7 mm;
width:13.5 mm). 4a-b. Dorsal and ventral views ofparatype C (Lenght: 24.7 mm; width: 13.5 mm).
5a. Protoconch ofparatype D. 5b. Paratype D, ajuvénile showing protoconch and first six whorls (Lenght: 4.1
mm; width: 1.9 mm).
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