DESCRIPTION OF A NEW SPECIES OF CRYPTOSOMA 



(C. AUSTENI). 



By WALTER E. COLLI NGE, E.Z.S., 

 Mason University College, Binniiighani. 



(Plate I.) 



(Read before the Midland Malacological Society, Aug. 12th, 1898.) 



The following description is from a single specimen sent to me from 

 Calcutta as a species of Helicarion. On referring to Godwin-Austen's 

 account of Cryptosoma prcestans, Gould, ^ and the figures which ac- 

 company the same, also specimens of the shell of C. prccslans, Gould, 

 in the Theobald Collection in the Museum of Mason University 

 College, and others in my own collection, it was at once evident that 

 this was a species referable to the genus Cryptosoma^ Theobald," the 

 differences, however, externally, and those in the form of the gener- 

 ative organs, necessitate its separation from C. prcestmis^ Gould, I 

 have therefore associated with it the name of Lieut-Col. H. H. Godwin- 

 Austen, F.R.S. 



Cryptosoma austeni, n. sp. 



Animal (PI. i, figs. 2 — 4) a light yellowish-brown, darker on the 

 head and posterior dorsum, which latter is sharply keeled. Right 

 shell-lobe moderately well developed, left shell-lobe very large. Right 

 dorsal lobe somewhat triangular in shape. Left dorsal lobe broad 

 and narrow, and rather darker than the right one, being finely si)otted 

 with black. Caudal mucous pore large, with no overhanging lobe. 

 Rugae large. Peripodial groove distinct, terminating at the dorsal 

 margin of the mucous pore. Foot-fringe same colour as the body, 

 with fine closely set lineolcs, extending to dorsal margin of the mucous 

 pore (PI. i, fig. 2). Foot-sole divided into median and lateral planes, 

 the former smoother and rather lighter in colour than the rest of the 

 body, the latter are transversely marked and similar in colour to the 

 rest of the body (PI. i, fig. 3). Extremity of foot-sole rounded (PI. i, 



fig- 3)- 



Length (in alcohol) 22-5 mm.; breadth of foot-sole in widest 

 portion, 4^5 mm. 



1 Land and Freshwater Mollusca of India, 1882, pt. i, p. 14, pi. iv, figs, i — 12^, 



2 Journ. Asiat. Soc. Bengal, 1857, p. 252. 



