590 



Records of the Indian Museum 



[Vol. XXII, 



The sides are slightly compressed, the anterior slope slightly con- 

 vex and the posterior slightly concave. The apex, which is 

 slightly eroded in the specimens examined is not greatly elevated, 

 blunt, not at all produced or recurved, but turned a little to the 

 right. It is situated in the posterior third of the shell. The 

 lower margin is very narrowly flattened and sometimes obscurely 

 retroverted. The whole of the external surface is smooth but 

 covered in the specimens examined by a thin minutely rugulose 

 deposit apparently of mineral origin. The interior has a dark 

 violaceous colour owing to a bluish white glaze on the deep 

 brown shell substance. It is marked with numerous concentric 

 rather blunt ridges, one of which, situated about f up the shell, 

 is sharp and more prominent than the others. There is usually a 

 band of white pigm.ent inmediately below the ridges. A micro- 

 scopic sculpture of very fine straight longitudinal radiating striae 

 can be detected under a high power, running from the inner 

 surface of the apex to the lip. Near the margin also there are 

 numerous transverse sinuate striae, equally minute, which give 

 the interior of the lip a faint iridescence. 



Fig. ig.^ShcW oi Ancyliis viola. Aniiandale and Pra^liad. 



Measurements of Shells (in millimetres). 



Length 



Breadth 



Height 



The animal is small as compared with the shell and no part 

 extrudes in progression. The whole surface is rather opaque 

 white with a clouding of black pigment on the head. The 

 snout is broad and bluntly rounded in front, the tentacles short, 

 and the eyes, which are black, are relatively large but not at all 

 prominent. The foot is rather narrow and bluntly pointed behind. 

 The left epipodial process is long and narrow. 



The buccal mass is stout and broad. The radula is relatively 

 large and as seen in a position of rest from above is band-shaped, 

 narrowing abruptly behind and apparently truncate in front 

 owing to a small anterior portion being bent downwards and in- 

 wards. The dental formula is approximately lo 8.1.8.10, but 

 the outer marginals are very imperlectly developed and the inner 

 marginals difficult to distinguish from the outer laterals. The jaw 



