250 PROCEEDINGS OF THE MALACOLOGICAL SOCIETY. 
HI. Chenui and H. ganoma, Pfr., approaching the latter in the more de- 
pressed spire and the want of solidity, and differing from both shells 
in its planate whorls and simple suture.” After some further remarks 
regarding H. Chenui, he alludes to the shell of H. Humphreysiana, 
Lea, as being somewhat similar on the under side, and it was very 
natural that he should make a comparison between these two large 
species.! 
I place the species under review in the subgenus Wilgiria; it agrees 
in all its chief characters with those species of that subgenus hitherto 
known to me, except in the dental formula and in the shape of the 
central and admedian teeth, which, curiously enough, are like those 
of Ariophanta (Indrella) ampulla (Bens.). 
I have more than once alluded to the distinctness of the molluscan 
genera of the family Zonitide in southern India and Ceylon. 
Nothing corresponding to them as far as the anatomy is concerned 
has been found for any distance outside the Peninsula area. Ario- 
phanta interrupta (Bens.) is an exception and was collected by me in 
the Jessore District, near Calcutta, having pushed its way thus far 
to the eastward, but I did not find it on the left bank of the 
Brahmaputra River. A. interrupta occurs on the right bank of the 
Ganges in the Rajmahal Hills, and could very easily be transported 
down that river and on to the area on the eastern side. ‘The land- 
shells of the delta must all have had their original home higher up 
the Gangetic valley on the one side, or the Brahmaputra on the other. 
It is interesting to find so many species of land mollusca in southern 
India and Ceylon differing so widely in the form of their shells and 
yet having the animals on a common plan. This feature, however, 
is met with in other families. A distinctly parallel case on a smaller 
scale may be noted even in the Zonitidee. In the western and eastern 
Himalayas the genus Bensonia is represented not only by large, strongly 
built shells, but also in the latter area by a thin and transparent form 
not yet described and unlike the first in every way. 
In Tenasserim and the Malay Peninsula we do not find molluses 
resembling Milgiria in their anatomy, but we find other typical 
eroups, Xesta and Hemiplecta, predominant, with characters of their 
own. Macrochlamys, from being the commonest form in Bengal, the 
Himalayas, and Assam, ranging to Burmah and even to the Andamans, 
is scarce in the Malay Peninsula, and I doubt very much if, when the 
species at present put into this genus from Malayana and Japan, ete., 
come to be dissected, they will be found to agree with the typical 
Indian forms. 
Up to the present time I have not seen a Macrochlamys from 
either Borneo or the Celebes. Species with shells somewhat lke 
those of IMacrochlamys, such as Lverettia consul, E. jucunda, and 
1 T may point out that in H. Humphreysiana, the type of the genus Hemiplecta, 
from Singapur, the animal differs from H. Basileus in many important characters, 
viz.: (1) the genitalia ; (2) the form of the teeth ; (3) the formula of the radula ; 
(4) the presence of shell-lobes, the most striking among the external characters ; 
and (5) the type of sole of foot. 
