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
Metalycaeus laosensis
Páll-Gergely
,
n. sp.
FIGUrE 47C
.
Type
material.
HOLOTypE
MNHN
IM-2012-27172
,
26
L04
NOrTHErN
LaOs
,
PHONGsaLy PrOvINCE
, OLd fOrEsT NEar sTrEam apprOx.
1 km
SW Of
a sTrEam aNd
Nam OU
(rIvEr) CONfLUENCE,
493 m
,
21°44.663'N
,
102°10.999'E
, LEG. A. AbdOU, I.V. MUraTOv, N. PHOTHIHOUmpHaNH, 0
4 DEC 2004
;
MNHN
IM-2012-27176
/1
paraTypE
,
5L05
NOrTHErN
LaOs
,
PHONGsaLy PrOvINCE
,
NE Of
PHONGsaLy
, aT NE parT
Of
PHOUfa MOUNTaIN rIdGE,
883 m
,
21°43.381'N
,
102°09.813'E
, LEG. A. AbdOU, I.V. MUraTOv, 0
7 Mar 2005
;
MNHN
IM-2012-27175
/1
paraTypE
,
35L05
NOrTHErN
LaOs
,
PHONGsaLy PrOvINCE
, OLd fOrEsT ON
THE
wEsTErN parT
Of
SEN
SI
LENG
TsU mOUNTING raNGE, dIvIdING
Nam
SING
NHa aNd
Nam
ONG,
1030 m
,
21°43.021'N
,
102°17.477'E
, LEG. A. AbdOU & I.V. MUraTOv,
24 Mar 2005
;
MNHN
IM- 2012-27174
/1
paraTypE
,
28L05
NOrTHErN
LaOs
,
PHONGsaLy PrOvINCE
, OLd fOrEsT NEar smaLL sTrEam aT
THE
UppEr
rEaCHEs
Of Nam
PUHa rIvEr basIN,
798 m
,
21°46.507'N
,
102°25.638'E
, LEG. A. AbdOU, I.V. MUraTOv,
21 Mar 2005
;
MNHN
IM-2012-27173
/1 (vEry smaLL, jUvENILE sHELL,
NOT
paraTypE
),
07L04
NOrTHErN
LaOs
,
PHONGsaLy PrOvINCE
, OLd fOrEsT ON PHOUfa MOUNTaIN (
1625 m
) jUsT
NOrTH Of
PHONGsaLy
,
1430–1618 m
,
21°41.333'N
,
102°06.493'E
, LEG. A. AbdOU & I.V. MUraTOv,
17–18 NOv 2004
.
Etymology.
Metalycaeus laosensis
n. sp.
Is NamEd afTEr THE COUNTry wHErE IT OCCUrs.
Diagnosis.
A mEdIUm sIzEd spECIEs wITH sHOrT, INfLaTEd R2 HavING CUrvEd rIbs (aT LEasT THE mOsT aNTErIOr ONEs), a vEry sHOrT R3, a dEEp CONsTrICTION bETwEEN R2 aNd R3, aNd a rEfLECTEd pErIsTOmE.
FIGURE 56.
Distribution of
Metalycaeus
species.
Filled triangle, top up.
Metalycaeus
(?)
okuboi
Páll-Gergely & Hunyadi
,
n. sp.
Empty triangle, top up.
Metalycaeus
(?)
ibex
Páll-Gergely & Hunyadi
n. sp.
Filled circle.
Metalycaeus
(?)
libonensis
(Chen, Li & Luo 2003)
.
Empty circle.
Metalycaeus latecostatus
(Möllendorff, 1882)
.
Empty square.
Metalycaeus sinensis
(Heude, 1882)
.
Filled square.
Metalycaeus rathouisianus
(Heude, 1882)
.
Description
(
FIGUrE 47C
). OrIGINaL sHELL COLOUr LIGHT brOwN TO GrEENIsH-yELLOwIsH, bUT mOsT sHELLs wErE sOmEwHaT wEaTHErEd; sHELL OUTLINE rOUNdEd frOm dOrsaL vIEw wITH CONspICUOUsLy INfLaTEd R2; spIrE rELaTIvELy sTrONGLy ELEvaTEd; bOdy wHOrL rOUNdEd; prOTOCONCH ELEvaTEd, spIraLLy sTrIaTEd, CONsIsTs Of 1.75 wHOrLs; bOUNdary bETwEEN prOTOCONCH aNd TELEOCONCH sHarp; R1 CONsIsTs Of 1.5 wHOrLs, wITH IrrEGULar, LOw, wIdELy-spaCEd rIbs aNd fINE spIraL sTrIaTION; TraNsITION bETwEEN R1 aNd R2 NOT CONspICUOUs, bECaUsE rIbs Of R2 INCrEasE GradUaLLy; R2 sHOrT, rEGULarLy, dENsELy rIbbEd, rIbs raTHEr sTraIGHT IN pOsTErIOr parT Of rEGION, rIbs GradUaLLy CUrvEd TOwards apErTUrE; R3 vEry sHOrT; bOUNdary bETwEEN R2 aNd R3 Is INdICaTEd by a dEEp CONsTrICTION; apErTUrE wIdE, rOUNdEd; INNEr pErIsTOmE NOT CONspICUOUs; OUTEr pErIsTOmE ExpaNdEd aNd rEfLECTEd (EspECIaLLy IN THE paLaTaL rEGION); bOUNdary bETwEEN INNEr aNd OUTEr pErIsTOmEs HardLy vIsIbLE; UmbILICUs dEEp.
Measurements (in mm).
D = 4.6–5.2; H = 3.6–3.8 (N = 3).
Operculum.
UNkNOwN.
Variation in specimens.
ExCEpT fOr sOmE mINOr dIffErENCEs IN sHELL sIzE, THErE arE NO NOTabLE dIffErENCEs bETwEEN
THE
spECImENs IN sHELL CHaraCTErs.
Differential diagnosis.
Metalycaeus laosensis
n. sp.
Is mOsT sImILar TO
M. awalycaeoides
n. sp.
dUE TO THE dEEp CONsTrICTION aNTErIOr TO R2 aNd THE rIbs, wHICH arE CUrvEd TOwards THE apErTUrE. HOwEvEr,
M. laosensis
n. sp.
Is LarGEr, Has a mOrE ELEvaTEd spIrE aNd a dEEpEr UmbILICUs, THE pOsTErIOr rIbs Of R2 arE NEarLy sTraIGHT, aNd IT Has a mUCH mOrE ExpaNdEd pErIsTOmE.
Metalycaeus muciferus
Has
sTraIGHT rIbs ON R2 aNd THE CONsTrICTION bETwEEN R2 aNd R3 Is sHaLLOwEr.
Distribution.
THIs NEw spECIEs Is kNOwN frOm fIvE LOCaLITIEs IN
PHONGsaLy PrOvINCE
,
NOrTHErN
LaOs
(
FIGUrE 57
).