Tg2i.J B, Prashad : Snmatran Molluscs. 471 



some specimens from ponds at Makassar. The elongate, slender 

 form of the shells clearly points to their having had this habitat. 



In the collection the specimens of this phase are from a 

 streamlet next Timbang I^angkat. 



var. porrecta, v. Martens. 



1H81. Liinnaea Javanica \ai". poi-yecta, v. Martens, op. cit., p. 89, pi. 



xvi, f\gs. Q, 10. 

 1897. Limiiaea javanica var. pon'ccta, v. Martens, op. ci'f,, p. S- 

 l8g8. Limnaea javanica var. poyrecta, Sarasin, P. and F., op. cit., p. 



89. 



This form, which is still more elongate than the var. angustior 

 and has a much longer and more regular spire, has been recorded 

 from Sumatra by von ^Martens. It is also known from Java and 

 the Kupaug Islands, Timor. 



The only specimens I assign to it were collected in a fresh- 

 water area near Tandjong Djatti (Langkat). All the specimens are 

 rather young, but I have no doubt as to their identification. 



var. costulata, v. Martens. 



1897. Limnaea javanica var. costulata. v. Martens, op. cit., p. 2, figs. 

 3-7, pi. xii, figs. 2, 4. 



This variety was described by von Martens from specimens 

 collected by Prof. ;\Iax Weber in Tjipanas, Java, and I have, 

 through the courtesy of Prof. Max Weber, had a chance of examin- 

 ing one of the co-types. 



Mr. den Doop's specimens are from a streamlet near Timbang 

 lyangkat, and a few young specimens from near Medan. The 

 costae on the shells are not so well developed as in the co-type, 

 but chere is no doubt that the shells belong to the variety. 



var. turgidula, v. Martens. 



1897. Limnaea javanica v.ir. turgidula, v. Martens, up. cit., p. 4, pi. 1, 

 fig. 6. 



This elegant form is known only from Sumatra. My speci- 

 mens closely agree with one of von Martens' co-types and his 

 figure of the shell. They were collected in the Valley of the 

 Lau Goemba' (Karo-Batak High-Plain) near Brastagei and from 

 the stream Soengei Ivandak (Upper L,angkat). 



Family Pi,anorbid.'\e. 



Genus Indoplanorbis, Annandale and Prashad. 



Recently Dr. Annandale '^ and I have found it necessary to 

 separate the common Indian species hitherto known as Planorbis 



1 I remember that I collected here many specimens of a Limnaea among 

 which there were some two per. cent of left-handed shells. They were from a little 

 rice-field in the valley beneath, [den Doop]. 



■^ Ind. Join-n. Med. Research, VIII, p. 113 (1920). 



