400 Records of the Indian Museum. [Vol,. XVI, 



it measures 26'5 mm. in total length, of which i'4 mm. is formed 

 b}' the proboscis. The greatest breadth at a point just behind the 

 middle is 7 mm., but this measurement is very unreliable as it 

 varies greatly with the state of expansion or otherwise at the time 

 of preservation. In general shape the animal is elongate, slightly 

 curved near the middle and pointed at both ends. 



The proboscis, the length of which is only one nineteenth of 

 the entire length of the body, is a rudimentary structure. Its cross 

 section a little behind the tip would be more or less of a semi- 

 circle, while near the base where the two margins are united the 

 structure becomes quite tubular. In appearance it resembles the 

 proboscis of T. sabinum described by me in another paper, ^ except 

 that the structure is at a much lower grade of development. The 

 two species agree in the lateral margins of the proboscis being 

 united ventrally at the base, but in other respects such as the 

 absence of finger-shaped outgrowths in the Indian form they are 



■%X^~' 



Thalassema micyorhyncliiis, sp. nov. 

 V'entral view of the proboscis and setal region, X 8. 



quite different from one another. The distal free end of the pro- 

 boscis is truncated. No cihated groove is to be made out on the 

 ventral surface but the inner surface anteriorly shows longitudinal 

 furrows. The dorsal surface is practically smooth. 



The body wall is covered with papillae, which near the two 

 ends of the body are arranged in definite rings ; between the rings 

 of large papillae rows of much smaller ones are also visible. On 

 the ventral surface of the body about the middle there is a cres- 

 centic area on which the adjacent papillae are united together to 

 form small elongated ridges, but the individuality of the papillae 

 can still be distinguished. The circum-anal region also shows 

 distinct papillae covering it. 



The ventral hooks are situated very near the anterior end ; 

 they are, as shown in the figure, very well developed and have the 

 free projecting portion of the hooks very broad and curved. 



i Mem. As. Soc. Bengal, VI, p. 325 (1919)- 



