MOLLUSCA OF INDIA. 53 



The teeth of the odontophore are arranged in 124 rows : — 



170 . 3 . 17 . 1 . 17 . 3 . 170 

 190 . 1 . 190 



The specimen here described was obtained from Mr. R. Damon, 

 who had received it from Mr. Brot, of Geneva. 



Original description (Ann. L3-c. N. H. 'New York, vol. vii. p. 158, 

 1858) : — " Testa dejiresso-globosa, tenuis Icevigata, pallide cornea ; 

 spira vLv elevata ; anfr. 3, celeriter accrescentibus, ultimo injlatn ; 

 apertura obliqua, coarctata, rotundato-quadrata ; perist. simplici, 

 margine columellari arcuato. 



" Diam. maj. 30, min. 24 ; alt. 15 mm. 



"Habitat Siam." 



Cetptosoma impekator, Gould. (Plate LXXII. figs. 1-6 a.) 



Vitrina imperatrix, A. A. Gould, Proc. Boston Soc. N. H. vol. vi. 

 p. 422 (1859). 



Several specimens, collected and preserved in spirit by Surgeon 

 Dr. R. Hungerford at Hongkong, were given to me by that excel- 

 lent ardent collector and oonchologist. The best-preserved specimen 

 measures 37 mm. in length ; it is of an ochre colour, wath indistinct 

 blotchings on the foot above and on the sides. The foot is not 

 keeled above, but rounded and rather flat near the posterior side of 

 the shell (fig. 2 a) ; here it has a central well-defined groove, from 

 which the lateral groovings on the side of the foot are given off. 

 The extremity of the foot is cut off straight. There is no over- 

 hanging lobe to the mucous gland (fig. 2 c), the vertical cleft 

 extending to the sole of the foot. The foot below has no central 

 area marked off from the sides, so conspicuous in G. p>rcestans, 

 O. imisitatum, &c. The segmentation of the pallial margin is con- 

 tinued for about 2 mm. beneath the foot and ends irregularly. 

 There is an indistinct peripodial row of oblong tubercles above 

 the pallial margin (fig. 2). The right and left shell-lobes are well 

 developed (figs. 1 6, 1 d, nat. size), and extend round and are con- 

 nected at the posterior median side. 



The generative organs (fig. 6) present a large amatorial organ, 

 with a blunt rod and short spermatheca, while the penis (fig. 6 a) 

 is very similar to that of the two preceding species. 



The jaw (fig. 4) is arched above, concave on cutting-edge, the 

 central portion nearly straight. The formula of the radula, which 

 was not quite perfect on the outside : — 



-f 65 . 4 . 11 . 1 . 11 . 4 . 65 + 



-1- 84 . 1 . 84 4- 



The central median teeth (fig. 5) as described in the last species. 

 The 11th tooth (fig. 5 a) is very long and narrow, with the small 

 tooth low down ; on the 12th, 13th, and 14th it is just indicated ; 

 the 15th is quite straight ; at the 16th the bicuspid teeth commence 

 and gradually diminish in size to the outside (fig. 5 b). 



