496 Records of the Indian Museum. [Vol. XXII, 



Good figures of this species are given by Reeve, von Martens 

 and Kobelt and all these closely resemble Ouoy and Gaimard's 

 fig. 18 (loc. cit.) of ''P. obtusum." The species is easily distin- 

 guished from P. obiusum by the shape of the shell, the mouth and 

 the much more delicate sculpture. 



There are only four specimens of this species in the collection. 

 These were collected along with those of P. obtusuui from the 

 mangrove-swamps at Belawan (Deli). 



Family Nassidae. 

 Genus Canidia, Adams. 



1861. Canidia. Adams, Proc. Zool. Soc. London, p. 383. 

 1876 Canidia, Brot, Journ. Conchyliol. XXIV, p. 343. 

 1897. Canidia, v. Martens, op. cit., p. 75. 



No specimens of this geijus were obtained by Prof. Weber in 

 Sumatra and the genus was described by von ilartens as being 

 unrepresented there. In 1900, however, he recorded the occurrence 

 of C. themenckiana from Lake Toba, Sumatra. In Mr. den Doop's 

 collection there are two specimens, one of which is referrable to 

 C. themenckiana, while the other is a specimen of C. liclena, which 

 has hitherto been recorded from Java and Timor. These two 

 records greatly extent the known range of the species. 



Canidia helena (Phil.). 



1897. Canidia Helena, v. Martens, op. cit., pp. 75, 76. 

 1912-13. Canidia Helena, Schepmann, op. cit., p. 236. 



The species was originally described as a Melania, and later 

 referred to the genus Melanopsis by Mousson, but Brot ' from an 

 examination of the radula and operculum referred it to its true 

 position amongst the Nassidae. 



There is a single specimen of the species in the Sumatran col- 

 lection from a fresh-water area near Medan (Deli). 



Canidia theminckiana (Petit). 



1853. Melania Theminckiana, VeUi, Joiirn. Conchyliol. I\', pp. 255, 



256, pi. vii, fig. 1 1. 

 1876. Canidia Tlieminckiana, Brot, Journ. Conchyliol. XXI V, p. 



347- 

 1900. Canidia Temminckiana, von Martens, Nachy. Deutsch. Malako- 

 zool. Ges. XXXII, p. 12. 



A single specimen collected along with that of C. helena is 

 referred to this species. It is quite like the figure of the species 

 and agrees well with Petit's description. 



Genus Clea, Adams 



1855. Clea, .Adams, Proc. Zool. Soc. London, p. iig. 

 1S76. Clea. Brot, op. cit., pp. 348-353. 



Journ. Conchyliol. XXIV, pp. 343-35'. P'- >'" (1876). 



