I92I ] 



S. L. HORA : Fish of Manipur. 



205 



Family MASTACEMBELIDAE. 



Rhynchobdella dhanashorii, sp. nov. 



Plate IX, fig. 2. 



D. 19/45. A. 3/47. C, 16. P. 17. 



. The length of the head is contained 7 times, of the caudal 14 

 times and the depth of the body 9 J- limes in the total length 

 including the caudal fin. The diameter of the eye is contained 

 about 5 times in the length of the head. The vent is situated nearer 

 to the base of the caudal fin than to the tip of the snout. The 

 mouth is small and does not extend to below the nostrils. There 

 are no preorbital or preopercular spines. The fleshy appendage of 

 the snout is broad and 

 concave with transverse 

 striations on the under 

 surface. Fins. — The first 

 dorsal consists of nineteen 

 spines, which increase in 

 length posteriorly except 

 for the last one which is 

 shorter than the rest. It 

 commences at the begin- 

 ning of the second third 

 of the distance between 

 the anterior end of the 

 orbit and the base of the 

 caudal fin. There are 

 three anal spines close 

 together, the middle one 

 is the longest. The caudal 

 fin is free both from the 

 dorsal and the anal fins. 



This species has a well-marked colouration. In spirit it is 

 dull olivaceous speckled with numerous very characteristic pale 

 lines extending downwards and forwards from the base of the 

 dorsal fin and becoming obscure in the bellj' region. Behind the 

 vent these lines are joined together in an irregular manner to form 

 a reticulation. A pale longitudinal band extends backwards from 

 behind the eye and becomes obscure in the post anal region. The 

 lower surface is pale, speckled with black on the lower surface of 

 the head. The fins are dark, minutely banded or speckled with 

 dull white. 



The only other known Indian species of the genus is Rhyn- 

 chobdella aculeata which is said to occur in brackish waters within 

 tidal influence and also throughout the deltas of large Indian and 

 Burmese rivers. The new species differs from it in having a 

 characteristic colouration and different proportions and also in the 

 fact that R. dhanashorii occurs far inland in freshwater. 



Text-fig. 



-I nder surface of head and snout 



of Rhynchobdella dhanasliorii, sp. nov. 



