one of these specimens that is represented in the Con. Indica (pi. xv, fig. 4) as
3 . akoutongensis, from Pegu. A few specimens were found by Dr. Anderson in the
2nd Defile, Irawady; they agree exactly with specimens from Shanghai in the
Indian Museum.
Specimen from 2nd Defile, Irawady : axis 6, diam. 15£ mm.
XLJUJriX tTLECTOTROPISj PERPLANATA,
Helix (Plectotropis) perplanata, Nevill, I. c., p. 19.
Only four specimens of this very remarkable form were found at Mimhoo,
Upper Burma; a larger series is required to prove with certainty whether it he a
distinct form, or only a variety of 3 . trichotropis, or of 3 . tapema (near var.
rotatoria).
After a most careful examination with a lens, I am unable to trace any sculpture
whatever dn the base; the seven whorls above are perfectly flat, as in the
European 3 . explanata ; the keel on the periphery and the shape of the aperture
are about the same as in 3 . trichotropis (especially the Khasi form); the umbilicus,
however, is considerably more open, quite twice as open as in the Chinese and the
above recorded specimens, and about half as open again as in those from the Kh&si
Hills; the epidermis seems peculiar, having the appearance of being less close in
texture and of a decidedly more developed character.
Axis 4^, diam. 17-g- mm.
H e l i x ( P l e c t o t r o p is ) o l d h a m i , Bens.
Helix oldhami, Bens., Ann. and Mag. Nat. Hist., 1859, ser. 3, vol. iii, p. 184; Con. Indica pi xv
fig. 7. V - V
Helix (Plectotropis) oldhami, Nevill, I. c., p. 19.
This species, well represented in the Con. Indica, is next affied to 3 . catostoma
and to 3 . tapema; the characters of the aperture distinguish it from the former,
the very open umbilicus, &c., from the latter. A single .specimen was found at Ava,
agreeing exactly with typical specimens from the Ara.ira.Ti Hills.
H e l i x ( P l e c t o t r o p is ) c a to sto m a , Blanf.
Helix (Trachia) catostoma, Blanf., Proc. Zool. Soc., 1869, p. 447.
Helix catostoma, Blanf., Con. Indica, pi. lvi, figs. 2, 8.
Helix (Plectotropis) catostoma, Nevill, I. c., p. 20.
The specimen figured in the Con. Indica is not taken from a typical Yunnan
specimen, but probably from one from Assam. The type in the Indian Museum,
found at Ponsee, on the Eirst Expedition, is the only adult specimen from Yunnan.
Nine or ten immature specimens were also found, but in none of them are the
HELICIDA1. 879
characters of the lip developed. 3 . catostoma was found tolerably abundantly in
the Naga Hills, by Major Godwin-Austen and Mr. Robert, and it is probably one of
their specimens that is figured in the Co.n. Indica. I'hey only differ from the type
by the less depressed spire and slightly less open umbilicus; the characters pf the
aperture' are the same, the dentiform process on the basal margin being equally
developed and characteristic in both.
H e l i x ( P l e c t o t r o p i s ) h u t t o n i , Pfr., var. s a v a d i e n s i s , Nevill.
Helix huttoni, Pfr., Symb. II, pfc. 3.
Helix (Plectotropis) huttoni, var. savadiensis, Nevill, I. c., p. 20.
The shell represented in Con. Indica, pi. xv, fig. 8, is not,* I think, a typical
specimen from the North-West Himalayas, but rather a specimen from Darjeeling;
the former, is a smaller, more rounded, and less solid shell, scarcely keeled at the
periphery, with , a higher spire and less produced aperture. A form found by
Dr. Anderson abundantly at Ava and Ponsee is nearer the Darjeeling form; the
spire is slightly-higher, with the apex more central. Seven specimens of a distinct
and remarkable variety were also found at Sawady; at first sight these present a
curious resemblance to H. arakanensis, and with that species are probably the connecting
link between 3 . tapema and H. huttoni, though unmistakably only a variety
of the latter; var. savadiensis differs by its more raised spire, stouter texture, and
less open umbilicus. 3 . wmteriana, v. d. Busch. (Java), seems to be a var. of 3 .
huttoni, differing by its more open umbilicus.
Specimen from Darjeeling: axis 5J, diam. 12^ mm.
Var. savadiensis, from Sawady: axis 7, diam. 12| mm.
H e l i x ( P l e c t o t r o p i s ) p h a y r e i , Theob.
Helix phayrei, Theob., Journ. As. Soe., Bengal, 1859; Con. Indica, pi. i, fig. 15.
Helix (Plectotropis) phayrei, Nevill, I. c., p. 20.
This is the largest species of the group, and is well figured in the Con. Indica;
it appears to be rare. I t is next allied to typical 3 . tapeina, the umbilicus being
exactly similar; the periphery, however, is merely angulate, not keeled; the sculpture
above is considerably coarser and more developed, the columellar margin more
oblique and slightly angulate at base, and the outer margin more produced and
rounded.
Sub-Genus T r a c h ia , Beck. -
H e l i x (T r a c h ia ) d e l i b r a t a , Bens.
Helix delibrata, Bens., Journ. As. Soc., Bengal, vol. v, 1886, p. 852.
Helix procumbens, Gld., Proc. Bost. Soc., vol. iv, 1844, pi. 53, t. 24, fig, 1.
Helix (Trachia) delibrata, Nevill, I. c., pi 21.