Systematic revision of the Plectopylinae (Gastropoda, Pulmonata, Plectopylidae)
Author
Páll-Gergely, Barna
31E196E9-5A51-4295-9A36-D5DA689502B7
Centre for Agricultural Research, Hungarian Academy of Sciences (MTA), Herman Ottó Street 15, Budapest, H- 1022, Hungary.
pall-gergely.barna@agrar.mta.hu
text
European Journal of Taxonomy
2018
2018-08-16
455
1
114
journal article
22297
10.5852/ejt.2018.455
44a2fcf6-cc1b-4c07-9554-dd6dd279a76d
3817707
C445E95B-446A-4601-AAA3-C1CCBAB627F9
Plectopylis cyclaspis
(Benson, 1859)
Figs 35I
,
41E
Helix catinus
Benson, 1859a: 185
[“prope Moulmein, provinciae Tenasserim”].
Helix cyclaspis
Benson, 1859b: 273
(nom. nov. pro
Helix catinus
Benson, 1859
, non
Helix catinus
Pfeiffer, 1857: 64
).
Helix revoluta
Pfeiffer, 1867: 64
[“in insulis Andamanicis”].
Helix
(
Plectopylis
)
cyclaspis
–
Benson 1860: 245–246
[“Farm Caves near Moulmein”]. —
Hanley & Theobald 1870: 7
, pl. 13, fig. 10. —
Godwin-Austen 1875b: 613
, pl. 74, fig. 10. —
Nevill 1878: 72
. —
Tryon 1887: 164–165
, pl. 35, fig. 9.
Plectopylis cyclaspis
–
Stoliczka 1871: 222–223
, pl. 15, figs 4–6. —
Gude 1897b: 244
, fig. 34a–d.
Plectopylis
(
Plectopylis
)
cyclaspis
–
Gude 1899d: 148
;
1899e: 175
;
1914b: 130–132
, fig. 65a–d; 1920: 63.
Diagnosis
A medium-sized, sinistral species with brownish purple shell and very conspicuous, sharp keel.
Type
material
Benson (1859a)
wrote the following in the original description of
Helix catinus
: “The single specimen transmitted for examination is in such a corroded state, that the true nature of the sculpture can merely be guessed at.” In the type collection of the NHM there are three shells having an intact sculpture with the following data: Damalthat, NHMUK 1898.12.04.1520–22,
3 syntypes
. These three shells surely do not represent type specimens of
P. cyclaspis
.
Fig. 41.
Shells and living specimens of species of
Plectopylis
Benson, 1860
.
A
.
P. crassilabris
sp. nov.
, holotype (UF 279203).
B
.
P. crassilabris
sp. nov.
(UF 346364).
C–D
. Living specimens photographed in the Khao Wong National Park, Aug.–Sep. 2010.
E
.
P. cyclaspis
(Benson, 1859)
(NHMUK 1888.12.4.1520–1522).
F
.
P. karenorum
(W.
Blanford, 1865
)
, probable syntype (NHMUK 1906.2.2.263). Scale bar: A–B, E–F = 10 mm; C–D not to scale. Photos: T. Deli (A), B. Páll-Gergely (B), S. Damrongsiri (C–D) and H. Taylor (E–F).
Material examined
MYANMAR
: 3 shells, Burma, Moulmein, coll. Oldham, Pres. 1951 (
NHMUK
); 2 shells, Moulmein (
NHMUK
);
2 juv.
shells, Moulmain, coll. Godwin-Austen (
NHMUK
); 4 shells, Molmein (
NHMUK
); 2 shells, Burma (
NHMUK
1871.9.23.48);
2 juv.
shells, Moulmain, coll. Godwin-Austen (
NHMUK
); 2 shells, Tenasserim, Moulmein, coll. Godwin-Austen, (“P.Z.S., 1874”) (
NHMUK
); 4 shells, Moulmein (
NHMUK
1906.2.2.148); 2 shells, Burma, Moulmein, coll. J.S. Hawkins (
NHMUK
1954.6.2.270–271); 3 shells, Burmah, Moulmein, coll. Salisbury ex Beddome (
NHMUK
).
Description
SHELL. Sinistral, strongly built, brownish purple, basal side lighter; protoconch consists of 2.75–3 whorls, matt, almost smooth or sometimes extremely finely granulated and roughly wrinkled; teleoconch irregularly wrinkled, without spiral lines; fresh shells with flat periostracal folds on keel; whorls 6.25– 6.5, strongly, sharply keeled, suture not conspicuous, an additional groove runs above suture; umbilicus narrow; aperture strongly facing downwards (in direction of ventral side); peristome conspicuously protruding in elongation of keel, which results in a concave bay between the parieto-palatal edge of peristome and the position of keel; peristome strongly thickened and reflected; parietal callus almost straight or very slightly S-shaped; apertural fold strong, free from parietal callus; umbilicus relatively narrow and deep.
Fig. 42.
Genitalia of
Plectopylis crassilabris
sp. nov.
A
. Whole genitalia (UF 376790).
B–E
. Inner structure of genital organs (B = penis, C = vagina, D = diverticulum, E = epiphallus) (UF 376790).
F
. Spermatophore, PL088 (UF 343899). Scale bars: A = 5 mm; B–F = 1 mm. For abbreviations see Fig. 2. All photos: B. Páll-Gergely.
Two opened shells were examined. Lambda-complex complete; left leg weak, right leg much stronger, has a very long anterior elongation; upper branch very long, parallel with upper suture; lower plica short, does not extend beyond lambda-complex; main plica absent. Palatal plicae typical of
Plectopylis
.
MEASUREMENTS (in mm). D = 18.9–19, H = 8.4–8.5 (NHMUK 148.06.2.2, n = 3).
CHARACTERS OF THE GENIAL STRUCTURE.
Stoliczka (1871)
published a description and drawings of the genitalia of this species.
RADULA. The characters of the radula of
P. cyclaspis
and
P. bensoni
(under the name
achatina
) were described by
Stoliczka (1871)
. According to him, the central tooth is very small, and the laterals have a large main cusp, and an ectocone with two or three cusps. This shape is unusual in the family
Plectopylidae
. Lateral teeth in all species of
Plectopylis
examined so far have a single large endocone, and a smaller ectocone with a single cusp. Therefore, the description of the radular teeth by
Stoliczka (1871)
is considered as inaccurate, probably due to insufficient instruments.
Differential diagnosis
Plectopylis cyclaspis
cannot be confused with any other plectopylid species due to its conspicuous keeled whorls.
Distribution
All known samples were collected in the vicinity of Moulmein (
Myanmar
). See also Remarks.
Remarks
Stoliczka (1871)
claimed that the
type
locality of
P. revoluta
(Andaman Islands)
is probably incorrect, because he received thousands of other shells from those islands, but none of them were plectopylids.
Gude (1914b)
concluded that
Plectopylis revoluta
(
Pfeiffer, 1867
)
is probably a synonym of
P. cyclaspis
. The species called
P. revoluta
in the recent literature is described here as
P. malayana
sp. nov.