264 JOURNAL, BOMBAY NATURAL HISTORY SOCIETY, Vol. XI. 



L. rufescens (Gray) is a shell of much more slender shape, and 

 up-country attains a size of 1^'X f" ; it is distinguished by the spire being- 

 very much produced, and by the obliqueness of the suture line. In 

 Bombay it seems not to exceed |"X &"; it is a slightly less fragile shell 

 than L. pinguis. It is not as a rule red, as its name would seem to 

 imply, but reddish specimens are occasionally met with. 



Of Planorbis we have two species. Shells of this genus are flat 

 spirals like rams' horns in shape. 



The first P. exustus (Desh.) is the larger, about |" in diameter and £" 

 thick, the aperture is of a crooked shape and generally longer than the 

 depth of the shell. The shell has a rugged appearance from marks of 

 old lips. 



It is common all over India, and has also received the names 

 coromandellcus (Kuster), indicus (Benson), and brunneus (Gray). 



The second, P. compressus (Hutton), is a little shell about \" in 

 diameter and very flat in shape, with no enlargement of the aperture. 



This species also is common all over India. 



In addition to these Gasteropoda, we have, according to Theobald, a 

 small bivalve in Bombay named Pisidium bombayanum. (Theo.), but I 

 have not yet found it, nor does it exist in the Society's collection. 



