i 9 i6.] 



Fauna of the Chilka Lake : Fish. 



449 



they are visible from below and not when looked at from above, not as in 0. boro, in 

 which the eyes are superior. The teeth in 0. hijala are pointed and not granular or 

 globular as in 0. boro. Kaup thought that (i O. hijala (H. B.) was the young fish 

 with less-developed teeth ' ' (p. 17). The full grown specimen in the collection falsi- 

 fies this contention. Hamilton Buchanan thought " 0. hijala did not grow above 

 eighteen inches in length." The present specimen which is longer by four inches 

 than the stated average length cannot therefore be said to be young. Day sunk the 

 specific name hijala (which he spells as " hyala" after Cuvier) in the synonymy for 

 0. boro, though in the body of his description of the fish under 0. boro he admits the 

 distinctive character of the teeth in 0. hijala by saying that the " teeth are conical in 

 the young, which character may be retained in the adult age as in 0. hiyala." It 

 should also be noted that in Hamilton Buchanan's work (Fishes of the Ganges) the 

 description of 0. hijala precedes that of 0. boro and is supported by a figure in the 

 published plates, whereas 0. boro follows 0. hijala and is not supported by any figure. 

 If therefore these two names of Hamilton Buchanan stand for one and the same species, 

 the name 0. boro should lapse and not 0. hijala. However, as has been shown above, 

 0. hijala is quite a distinct species. 



Hamilton Buchanan's published figure of 0. hijala is however defective (Plate V, 

 fig. 5). The pair of tubular nostrils (the tag-like organs on the snout) are shown to 

 be attached on the superior surface of the snout and are directed upwards in the 

 figure, whereas they are on the underside of the snout, are lateral and inferior and 

 are directed downwards. The eyes are shown to be above the angle of the jaw, 

 whereas they are actually situated about the middle of the opening of the mouth. 



There is a figure of this snake-eel in Hamilton Buchanan's manuscript drawings 

 (p. 443 ante) on plate No. 27 of the set. The name on the back of the plate in Hamil- 

 ton Buchanan's own handwriting is Ophisurus rostrata. This is the original and per- 

 haps the only source of the name and description of " Ophisurus rostratus " of M'Clel- 

 land in volume V of the Calcutta Journal of Natural History, pp. 184 and 211. 

 Hamilton Buchanan chose to alter his manuscript name "rostrata" to "hijala" in 

 his published work " The Fishes of the Ganges." It is this rejected manuscript name 

 of Hamilton Buchanan that was restored by M'Clelland through mistake. He says 

 " I have not met with this species." 



The following measurements of this unique specimen are of interest : — 

 Length of head . . . . . . . . . . 52 mm. 



Length of snout . . 



Diameter of eye . . 



Interorbital space 



Length of upper jaw 



Length of lower jaw 



Snout to vent 



Tail 



Free portion of tail 



Distance between gill-openings and the origin of dorsal fin 



Length of pectoral fin 



7 

 5 



7 

 11 



9 



215 



350 



4 



32 



12 



