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
Chersaecia nagaensis muspratti
(Gude, 1897)
comb. nov.
Figs 21J–K, 22B
Plectopylis muspratti
Gude, 1897f: 10
, fig. 45a–f [“
Naga
Hills,
Assam
”].
Plectopylis muspratti
–
Gude 1898h: 7–8
, fig. 5a–f.
Plectopylis
(
Chersaecia
)
muspratti
–
Gude 1899d: 148
;
1899e: 175
;
1914b: 89–90
, fig. 37a–f.
Chersaecia muspratti
–
Páll-Gergely
et al.
2015c: 10
.
Diagnosis
A subspecies of
Chersaecia nagaensis
lacking the main plica.
Material examined
Syntypes
INDIA
: 2 shells, (diameter of photographed shell =
11.7 mm
), Naga Hills, coll. Beddome (
NHMUK
1912.4.16.320).
Description
The description of the external shell is based on two
syntypes
deposited in the NHM. No additional material was found in that collection.
Gude (1897f)
described and figured the inner plicae based on the shells in Colonel Beddome’s collection. Therefore, the original description of the plicae is copied from
Gude (1897f)
.
SHELL. Sinistral, with elevated spire, dorsal side conical; one of the shells corroded, but the other has a yellowish grey basic colour with reddish stripes, which results in a mosaic-like colouration on dorsal side; protoconch matt, almost smooth or with irregular growth lines; teleoconch with fine reticular structure; whorls 6–6.5 (n = 2), separated by rather deep suture; whorls rounded, not angled; peristome reflected and slightly thickened, parietal callus normally developed, S-shaped; apertural fold shorter than parietal callus, connected to it.
“Parietal wall with a short entering flexuous fold united to the ridge at the aperture, becoming attenuated inwardly, and at one-third of the circumference from the aperture, with a strong, crescent-shaped vertical plate, which is suddenly deflected posteriorly at the lower extremity; below this, on the anterior side, occurs a very short, horizontal fold. Palatal folds six, horizontal, short the first free, with a small denticle posteriorly; the second, third, fourth, and fifth connected with each other by a vertical ridge, which deflects below the fifth fold posteriorly and terminates in a small, oblique denticle; the sixth again free” (
Gude 1897f
).
MEASUREMENTS (in mm). D = 11.7–12.9, H = 6.6–6.75 (
syntypes
, n = 2).
Differential diagnosis
Chersaecia nagaensis muspratti
differs from the nominotypical subspecies by the absence of the main plica.
Distribution
The subspecies is known only from the
type
locality.
Remarks
The only notable difference between
Plectopylis nagaensis muspratti
and
P. nagaensis nagaensis
is the presence (
nagaensis
) or the absence (
muspratti
) of the main plica. Since there is no difference in the general shell or aperture shape, I assign
P. muspratti
as a subspecies of
P. nagaensis
.