Revision of the Alycaeidae of China, Laos and Vietnam (Gastropoda: Cyclophoroidea) I: The genera Dicharax and Metalycaeus
Author
Asami, Takahiro
text
Zootaxa
2017
2017-10-11
4331
1
1
124
journal article
31855
10.11646/zootaxa.4331.1.1
14c29731-224f-43a4-ae52-f76823177ce5
1175-5326
1009725
FB50725E-4D03-4507-9CAF-EB939C7F548F
Dicharax microcostatus
Páll-Gergely
n. sp.
FIGUrE 34C
.
Type
material.
HOLOTypE
HNHM 99708
, PGB/1
paraTypE
(
Ex
COLL
. K. OHara),
20070709B
CHINa
,
SICHUaN
, TaIaN
ZHEN
, QINGCHENGHOUsHaN, DUjIaNGyaN
SHI
, CUIyINGHU TO
UppEr sTaTION
Of
JINLI
CabLE sTaTION,
1273 m
,
30°56.27110'N
,
103°28.75198'E
, LEG. Y.
NakaHara
, K. OHara, K. OkUbO &
J.U.
OTaNI, 0
9 JULy 2007
; HA/1 wEaTHErEd sHELL (
NOT
paraTypE
),
2015/48
CHINa
,
SICHUaN
, CHENGdU
SHI
, DUjIaNGyaN
SHI
, QINGCHENGHOUsHaN, UNdEr BaIzHaNG BrIdGE,
1220 m
, 30°56.088'N, 103°28.818'E, LEG. A. HUNyadI & M. SzEkErEs, 0
5 JUNE 2015
.
Etymology.
THE spECIfIC EpITHET rEfErs TO THE smaLL sIzE aNd rIbbEd sHELL Of THIs NEw spECIEs.
Diagnosis.
A smaLL spECIEs wITH rIbbEd R1, sHOrT R2 aNd R3, sHarp swELLING ON R3 aNd CrENULaTEd pErIsTOmE.
Description.
SHELL (
FIGUrE 34C
) yELLOwIsH; sHELL OUTLINE rOUNdEd frOm dOrsaL vIEw, spIrE sLIGHTLy ELEvaTEd, EdGE Of bOdy wHOrL rOUNdEd; prOTOCONCH LOw, CONsIsTING Of 1.5 wHOrLs, wE Had ONLy wEaTHErEd maTErIaL THErEfOrE sCULpTUrE COULd NOT bE ExamINEd; R1 CONsIsTs Of 1.75 wHOrLs, rEGULarLy, fINELy rIbbEd; TraNsITION bETwEEN R1 aNd R2 raTHEr smOOTH; R2 vEry dENsELy rIbbEd, rIbs CUrvEd TOwards apErTUrE; CrOss-sECTIONaL vIEw Of R2 COULd NOT bE ExamINEd, bUT prObabLy sImILar TO THOsE Of THE OTHEr spECIEs HavING CUrvEd rIbs; COmbINEd LENGTH Of R2 aNd R3 sHOrT, apprOxImaTELy 70 dEGrEEs ONLy; R2 aNd R3 Of abOUT THE samE LENGTH; TraNsITION bETwEEN R2 aNd R3 CLEarLy vIsIbLE dUE TO sLIGHT CONsTrICTION bETwEEN R2 aNd R3; ENd Of R3 wITH a CONspICUOUs swELLING; R3 smOOTH aNd GLOssy; apErTUrE rOUNdEd, pErIsTOmE ExTErNaLLy sLIGHTLy CrENULaTEd; INNEr LIp THICkENEd, OUTEr LIp vEry wEak bUT sHarp.
Measurements (in mm).
D = 3.1, H = 2.0–2.2 (N = 2,
TypE
sampLE).
Operculum.
THE INNEr sUrfaCE COULd NOT bE ExamINEd, bUT a
CENTraL
NIppLE Is dIsCErNIbLE dUE TO THE sEmI- TraNsparENT CHaraCTEr Of THE OpErCULUm. THE OUTEr sUrfaCE Is sEEmINGLy smOOTH, NO mULTIspIraL
LamINa Is
vIsIbLE.
Variation in specimens.
THE
fEw kNOwN ExampLEs sHOw LITTLE varIabILITy IN sHELL CHaraCTErs.
Differential diagnosis.
Dicharax microcostatus
n. sp.
CaN bE dIsTINGUIsHEd frOm aLL CHINEsE aNd VIETNamEsE CONGENErs by THE smaLL sHELL sIzE aNd THE vEry sHOrT R2.
Dicharax draco
n. sp.
Has a mOrE ELEvaTEd spIrE aNd a mUCH mOrE sTrONGLy CrENULaTEd pErIsTOmE. THE vEry varIabLE
Dicharax fimbriatus
dIffErs frOm
D. microcostatus
n. sp.
by THE LONGEr R2 aNd R3, aNd THE swELLING ON R3, wHICH Is sITUaTEd IN GrEaTEr dIsTaNCE frOm THE pErIsTOmE, THaN IN THE NEw spECIEs. SEE UNdEr
Dicharax micropolitus
n. sp.
Distribution.
Dicharax microcostatus
n. sp.
Is kNOwN frOm THE
TypE
LOCaLITy ONLy (
FIGUrE 7
).