512 Memoirs of the Indian Museum. [Voe. V, 



Piscicola olivacea, n. sp. 



(Fig. i.) 

 Form, Size, Colour. 



The circular and exceedingly long and slender body of this little leech re- 

 sembles in. general form that of the Piscicola geometra of Europe. It is about half the 

 size of the European species, the largest example measuring, when fairly extended, 

 approximately 1075 mm, in total length, the greatest width of the body being 

 about 1*50 mm. 



For information as to colour, I am dependent upon Dr. Annandale, who has 

 been good enough to send me notes upon the external features of several different 

 individuals. From these notes it appears that the general colour of the body 

 varies from bright to pale olive green, minutely speckled with black, or with a 

 darker shade of green. A series of conspicuous white spots occur, one on either side 

 of each somite, on the margins of the body, and these are connected across the 

 dorsal surface by whitish and often indistinct bands. 



Another series of somewhat irregular elongated spots or blotches lie in the mid- 

 dorsal line, one in each somite (on a level with the marginal spots) and these median 

 spots, which may or may not be joined together at their extremities, give the appear- 

 ance of a somewhat ill-defined whitish mid-dorsal streak. 



Anterior sucker circular, whitish, with three brownish bands on the dorsal 

 surface ; one band following the junction with the body, one near the anterior tip 

 and a third and broader one between the two, in the posterior part of the sucker, 

 which contains the eyes. The mouth-opening is situated in the centre of the interior 

 cup. 



Posterior sucker somewhat heart-shaped, of the same green colour as the body, 

 with seven pairs of whitish rays, corresponding to the seven somites xxviii-xxxiv 

 of which it is composed. 



Several individuals examined showed traces of the original dorsal pattern, and 

 from one of these the arrangement of spots and bands shown in Fig. 1 was drawn. 

 It is to be understood that the arrangement indicated is schematic and subject 

 to a good deal of variation in its details. 



Rings, Somites, Genital Organs, Eyes. 



The complete somite is formed of 14 annuli. 



The transverse middle line of the complete somite passes through a ventral 

 ganglion, and also through the middle of the white mid-dorsal and marginal spots. 

 The ganglion occupies two rings (7 and 8) of the complete somite. 



The pulsating vesicles have collapsed in the specimens examined, but traces 

 of them occasionally may be seen, and their presence is placed beyond doubt by 

 Dr. Annandale, who has noted that they occur in the whitish spots on the margins of 

 the body. The first pair lie in somite xiii, and there appear to be eleven pairs, 

 the last pair lying in somite xxiii. 



