inhabiting India and China. 349 
It is a very local species, but abundant in the places indicated. 
Besides size, it differs from the Chusan species in sculpture, in 
its more angular form at the periphery, and in its less excavated 
lower disc, and narrower umbilicus. It is somewhat singular 
that the only species of Planorbis which have been observed with 
internal lamine, should inhabit such widely separated localities 
as westernmost Europe, the eastern part of Asia (both of them 
insular situations), the north-western part of India, and the mouth 
of the Ganges. Planorbis umbilicalis, nobis (Journ. As. Soc. 
vol. v.), an allied Bengal form, is utterly destitute of any internal 
teeth or lamin, as is also the species next to be described. 
3. Planorbis cenosus, nobis, n. s. 
Testa nitida, luteo-cornea vel olivaceo-cornea, oblique et rude (preecipue 
subtus) radiato-striata, subdiaphana, supra depresso-convexa; spira 
parvula, apice excavato ; sutura impressa; anfractibus 3}, ultimo 
majori, extus depressiusculo, inferne carinato, subtus planato, versus 
umbilicum majorem leviter excavato ; apertura obliqua, sagittiformi, 
margine superiori arcuato, prominente, inferiori recedente, recto. 
Diam. maj. vix 6 mill., minor 5, axis 1}. 
Hab. in stagno prope urbem Moradabad, agris Rohillanis. 
Less abundant and still more confined in locality than Pl. Ca- 
lathus. The specimens taken by Dr. Bacon and myself were 
supposed to be merely a large variety of that species, but on 
clearing them, lately, from a thick ochreous deposit with which 
they were disfigured, I perceived that not only were they 
destitute of internal laminz, but that the shells were more de- 
pressed and more angular at the keel, and that the relative pro- 
portions of various parts differed. 
4. Planorbis Cantori, nobis, n. s. 
Testa nitidula, cornea, subdiaphana, radiato-striata, depressa, supra 
convexiuscula, spira planata, apice concavo, sutura bene impressa ; 
anfractibus 53, convexiusculis, lente crescentibus, ultimo antice 
majori, subtus convexo, periphzeria subcarinata; umbilico aperto, 
profundiusculo; apertura obliqua subcordiformi, margine supra 
valde arcuato, fuscato, infra leviter rotundato. 
Diam. maj. 7, minor 64, alt. 2 mill. 
Diam. spire 31; lat. anfract. ult., antice, 3 mill. 
Hab. in stagnis Bengalensibus prope castra Barrackpore. Teste Theo. 
Cantor. 
This shell, of a sublenticular form, is intermediate between the 
subtrochoid species and the more symmetrical smaller Planorbes. 
It comes much nearer to P/. convexiusculus, Hutton, Journ. As. 
Soe. Calcutta, July 1849, than P. umbilicalis, nobis, which, from 
the tenor of his foot-note in page 657, Capt. Hutton has never 
seen. The forms of the European and American shells with 
