1865.] Contributions to Indian Malacology. 75 
Tsanda Khyoung, it was abundant, but it was not met with again 
until 3 or 4 specimens of the larger variety were found nearly 50 
miles further south. 
The locality given by Mr. Benson for Helix leiophis is Kwadouk 
near Thayet Myo. The shell also abounds at Akoutoung, on the 
Trawady, below Prome. 
13. H. perarcra, n. sp. 
Shell sinistral, widely umbilicated, discoid, rather thin, white, 
transversely sinuously striated, with faintly marked decussating spiral 
lines above and below. Apex minutely granulate, slightly raised 
above the flat spire, suture rather deeply impressed. Whorls 6, 
convex above and at the periphery, the last a little compressed behind 
the mouth, descending suddenly to the aperture, which is oblique and 
roundly lunate ; peristome white, expanded all round; margins joined 
by a somewhat’ curved ridge, from the centre of which a lamella runs 
up the whorl towards the parietal plication, which, however, it does 
not join. The parietal vertical lamina is single, simple, rather short, 
slightly curved, with a rudimentary transverse plait at the top. Two 
free horizontal lamella occur beneath that running to the aperture, the 
lowest being the longest and thinnest, and running back beneath the 
base of the vertical lamina. Palatal teeth 6, all horizontal except the 
4th and 5th, which are slightly oblique. Umbilicus open, deep, 
exposing all the whorls. 
Millem. inch. 
Major diameter,......s00.0..0.008 11 0.44 
Emon IG ttOy LY. 0k UE 9 0.36 
Efoieiht picts Reged eas: 4 0.16 
Habitat—Mya Leit Doung, near Ava. 
Distinguished from its allies, H. refuga, H. leiophis, and H. Kareno- 
rum, by its deeper suture and rounded whorls, and internally by the 
shorter parietal lamina, and by the 5th palatal plait being less oblique 
than in leiophis, and not backed by a second plait as in refuga. This 
species is the smallest known amongst those belonging to the Burmese 
types of Plectopylis. 
14. H. Feppeni, n. sp. 
Shell sinistrorse, very widely umbilicated, discoid, flat above, thin, 
dull white, marked by rather irregular oblique sculpture both above 
