7IO Records of the Indian Museum. [Vol. XXII, 



Family GNATHOBDELLIDAE. 

 Genus Whitmania, R. Blanchard. 



20. Whitmania lacvis (Baird), 1869. 



Hirudo laevis, B.iird. i86g. 

 Leptosioma pigyiim, Whitman, 1886. 

 Whilmania pigra, R. Blanchard, 1887. 



The two examples which I have identified with Whitmania 

 laevis were collected b}- the Manipur Survey party at Pagla Nadi 

 and from Thanga Island. This species is v&xy wide in its dis- 

 tribution, being well known to occur in Japan, the Amur region, 

 China, the Philippines, Malacca, India, Celebes, Sumatra and 

 elsewhere. 



The body is large and tapers considerably towards the anterior 

 end. A short distance behind the anterior tip is a slight con- 

 striction in the specimen from Thanga Island. The specimen 

 from the latter locality is of larger size than that from Pagla Nadi, 

 and is about 140 mm. in length and i8 mm. in breadth at the 

 middle of the body. 



The anterior sucker is very small, lying ventrally within the 

 limits of rings i-6. The jaws, presenting three small alternate 

 folds, are devoid of proper denticles, but are beset with two 

 series of irregular, thin denticular plates, which are more or less 

 united, especially at the outer and inner angles, where the two 

 series bend, as mentioned by Whitman, into each other. 



The posterior sucker is somewhat ventrally attached and 

 circular in outline, about 8 mm. in diameter. 



The body is formed of 107 rings, of which rings 6 and 7 are 

 fused ventrally to form the posterior boundary of the anterior 

 sucker, and rings 8 and 9 are also united on the ventral side. On 

 the dorsal side coalescence is found between the two rings of 

 somite xxvi. The same is true of the last two rings. All the 

 rings are grouped, as usual, into twenty-seven somites as follows: 

 somites i, ii and iii are uniannulate, iv, v, xxvi and xxvii biannul- 

 ate;vi triannulate; vii and xxv quadriannulate ; the seventeen 

 somites viii-xxiv are complete with five rings. 



The five pairs of eyes are arranged as in Hirndo, that is in 

 rings 2, 3, 4, 6 and 9 respectively. 



The segmental papillae are so regularly arranged as to exhi- 

 bit six longitudinal rows on both sides, dorsal and ventral. In the 

 complete somites they occur on the middle ring. 



The male genital orifice in the two examples from Manipur 

 occurs in the middle of ring 34, that is on the last ring of somite 

 xi, and the female orifice is five rings behind the male, that is 

 slightly anterior to the centre of the last ring of somite xii. 

 Occasionally both the orifices are displaced near the anterior edge 

 of the corresponding rings, appearing, in preserved specimens, to 

 He between the rings. In an example from Japan included in the 

 collection the male and female openings appeared to be respec- 

 tively between the last two rings of somites xi and xii. 



