52 I,AND AND FRKSUVVATER 



the radula is very broad, with 132 rows of teeth, arranged :— 



140 . 3 . 17 . 1 . 17 . 3 . 140 

 160 . 1 . 160 



In another I counted 165. 



The teeth (figs. 6, 6 a) differ considerably from those of C. prce- 

 stavs from Moulmain. The central tooth is long, with the side 

 cusps about halfway between the point and the posterior margin of 

 the plate. The side centrals are broad with one outer cusp, none on 

 the inner side ; the outermost are on long and narrow bases, with 

 short, bifid, rather rounded, bud-like points. The jaw (fig. 5) is 

 curvilinear, with a well-defined central projection, thus difi^ering 

 from C. prcestans. 



A bottle containing several specimens of this species and a 

 smaller form like 0. veunstum, sent me by Colonel Woodthorpe from 

 the Shan plateau, was, owing to the weakness of the spirit, in such 

 a state that no description or use could be made of them, but 

 on looking them over I discovered a spermatophore in a fair state 

 of preservation, only the side spines readily coming off". The mem- 

 branaceous sac was short, 3 mm. long, or about one-third of the 

 whole length ; the spines are bifid, and set at intervals upon the 

 long shaft (fig. 8). 



The shell of C. inusilatum (figs. 1,1a) differs from C. prcestans 

 (figs, 2, 2 a) in being much more fragile and more depressed. The 

 genitalia are on the same model, but the amatorial organ of 

 C. inusitatum is larger. The greatest diff'erence is found in the 

 minor details of the jaw and radula, the jaw in C. pr(xstans being 

 very straight. 



Cryptosoma siamense, Haines. (Plate LXXI. figs. 1-5 a.) 



Animal (from spirit-specimen, through Mr. K. Damon). Shell 

 and neck -lobes (figs. 2, 2 a) as in C pra'stans, with this diff'erence, 

 that they are coarsely and evenly papillate throughout, giving them 

 a shagreened appearance. The colour is darkish grey throughout 

 as far as the pedal line, leaving the pedal margin distinctly paler. 

 The foot is not so definitely divided. 



The generative organs (fig. 5) do not diiFer very materially from 

 the type of the genus. The amatorial organ is shorter and broader, 

 and the spermatheca has a small, globose, free end. The vas 

 deferens is short. 



The jaw (fig. 3) is curved above, flatly concave on the cutting- 

 edge, with no decided central projection. The central teeth are 

 numerous and large, with a cusp on the outer side (fig. 4) ; about 

 the 18th and 19th (figs. 4 a, 4 h) l\\ej become narrower and elon- 

 gate ; the 20th has no cusp ; in the 21st its position is high up, 

 just below the main apex ; from the 22nd outwards all are bicuspid. 

 The outermost laterals (fig. 4 c) are very narrow, with long basal 

 plates with bicuspid bud-like points. 



