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



Bithynia truncata, Eyd. and Soul. 



1897. Bithynia tvxincata, v. Martens, op. cif., pp. 25, 26, pi. ix. figs. 

 1 1, lli. 



B. truncata had not hitherto been recorded from Sumatra but 

 was known only from Java and Celebes. In Mr. den Doop's collec- 

 tion there are a fair number of specimens from fresh-water areas at 

 Med an and near Padang Boelan. The specimens are typical 

 and agree fairly well with the detailed description in von Martens' 

 paper. 



Family Littorinidae. 



Genus LittorJna, Fer. 



Subgenus Littorinopsis, Morch. 



The four species of this subgenus from Sumatra all belong to 

 the subgenus Littorinopsis, Morch. All these species are rather 

 thin-shelled forms not exceeding 25 mm. in length. 



Littodna scabra (Linn.). 



1897. Littoi'ina scabra, v. Martens, op. cit., pp. 194-196. 

 There are eight specimens of this species collected from a 

 mangrove-swamp at Belav.'an (Deli). All the specimens are fair- 

 ly typical, showing only slight variation in colour. 



Some features of the gross anatomy of this species are 

 shown in Quoy and Gaimard's figures ' and the radula has been 

 figured by Troschel. ■^ 



Littorina intermedia, Phil. 



1897. Littorina intermedia, v. Martens, op. cit., p. 197. 



In the paper cited above von Martens has given the complete 

 synonymy, and discussed the distribution of this widely distri- 

 buted species. 



In the Sumatran collection it is represented by a large number 

 of specimens from the sea-shore at Perbaoengan (Sardang), and 

 a few from the Soengei Belawan (Deli), not far from the sea. 

 All these specimens closely agree with the large series of this 

 species in the Indian Museum collection from various localities. 



Littorina carinifera (Menke). 



1897. Littorina carinifera, v. Martens, op. cit,, p. 198. 



This widely distributed species is represented in the collection 

 by a few individuals from the mouth of the Soengei Batang Kwis 

 (Serdang) and from a mangrove -swamp at Belawan (Deli). 



The specimens closely agree with Menke's and von Martens' 

 descriptions, but show a slight variation in colour. 



1 Op. cit., p. 770, pi. xx.xiii, figs. 1-3. The species is referred to as Littori- 

 la angiilifern (Lam.). 



' Das Gebiss der Sclinecken, 1, sp. 133, pi. x, fig, 18. 



