280 LAND AND FRESHWATER 



rounded, scarcely rising above last whorl ; suture very shallow ; 

 whorls 8, rapidly increasing, the last ample; aperture broadly 

 lunate ; peristome thin. 



Size : maj. diam. 20-0, min. 15'5 ; alt. axis 6*0 mm. 



This shell, the largest I have seen of the geuus, from its great 

 size compared with other species included in it, and from the 

 description, can be no other than the above described by Henry 

 Blanford in 1871, and figured on plate ii. ; the shells on this 

 ]date were drawn by me in 1869 when staying with him at 

 Calcutta. I have never seen this shell heieroconcha since, for it is 

 not in his collection of shells at the Natural History Museum : 

 its rediscovery at 8iliguri is therefore important. It was originally 

 found by Mr. W. !S. Atkinson, of the Educational Department, 

 vho was a great collector of Lepidoptera, and Siliguri was no 

 doubt often visited by him. 



The animal (fig. 3) is white throughout, no markings; this 

 whiteness may, I think, be attributable to the alcohol, for all the 

 other specimens with it are in the same colourless state. The foot 

 is truncate behind, slightly produced, and overhanging the linear 

 mucous pore above ; peripodial margin wide, and a well defined 

 central area on the sole ; right shell-lobe is elongate, rounded, 

 papiilated, some papilli being very large and conspicuous ; left 

 shell-lobe on wide base extending from near the respiratory 

 orifice to hinder part of the visceral mass, triangular in shape, 

 with a similar papillate surface ; visceral sac grey. 



Tlie genitalia (fig. 3 a) are on the same plan as C. succinea = 

 j^lanospira, Bs., vide\o\.J. p. 149, Plate XXXVI. The amatorial 

 organ is large and cylindrical, with a large, long and strong retractor 

 muscle. The penis is a short stout tube, with a thick, very short 

 retractor muscle attached to the wall of the branchial cavity, the 

 vas deferens joins it at the apex and is short in length ; the 

 spermatheca is short and bulbous. The rest of the generative 

 system does not call for any notice. 



The radula was extracted quite perfect. The central tooth is 

 tricuspid, the admedians have a small inner cusp just below the 

 point and one basal outside ; the first 15 marginals are bicuspid 

 with the inner unicli the longest, this gradually rises higher, and 

 the outermost are evenly bicuspid. The teeth are arranged : 



72 . 2 . 17 . 1 . 17 . 2 . 72 = 91 . 1 . 91. 



The teeth are similar in shape to those of Girasia magnijica, vide 

 Plate LXII. fig. 2. 



The jaw was not well preserved. It was concave on the 

 cutting-edge, and there was no indication of a central projection. 



Original description : — " Testa valdc depressa, peripluHd ovali, 

 tenuis, diaplicma, subtus membranacea, luleo-cornea, versus cqtei-turam 

 viridicans, 2'>oUta, arcuatim obsolete striata, versus apertiiram irregn- 

 lariter stibcoslulata. Sj>!ra planata, apice vix exserto. Anfractus 3, 

 rapide accrcscentes ; idAimus dilalaius vix desccndcns. Sutura 



