44 Memoirs of the Indian Museum. [Voiv. II, 



ventral surfaces, the flabby consistency of its muscular tissue, and the structure of the 

 interior of its mouth and teeth, the cusp of the latter being very wide transversely and 

 forming a flat triangle rather than a spine-like process. 

 The Indian species may be recognized as follows : — 

 I. Dorsal .surface spotted. Dorsal fins subequal . . . N . timlei. 



II. Dorsal surface brown ; ventral surface white. Dorsal fins sub- 

 equal . . . . . . . . . . N . hrunnea. 



III. Dorsal and ventral surfaces dark brown, unspotted. Dorsal fins 



subequal . . . . . . . . . . N . mollis. 



The eyes in all the Indian species are large, and the margins of the spiracles are 

 smooth. 



Navcine timlei (Bloch and Schneider). (PL ma, fig. i.) 

 N. timlei and N. indica, Henle and Midler, op. cit., p. 130. 

 N. timlei, Günther, op. cit., p. 452; Day, op. cit., vol. i, p. 45 (in part, not the 



figure) ; Fishes of India, vol. ii, p. 733 (in part). 



Disk variable in outline, sometimes regularly oval and only slightly broader than long, 

 sometimes considerably narrower, sometimes with the pectoral fins projecting 

 in such a way that it becomes, even in fresh specimens, almost rhomboidal. 

 The tail strongly developed, depressed, nearly as long as or longer than 

 the disk ; the two dorsal fins subequal, separated by about the length of one of 

 them ; the posterior margin of the pelvic fins reaching or nearly reaching the 

 anterior border of the first dorsal. Extent backwards of the pectorals variable ; 

 sometimes they fall short of the anterior margin of the pelvic fins, sometimes reach 

 it, and frequently overlap it. 



Colour. — ^Dorsal surface chocolate-brown (which sometimes turns to purplish grey in 

 preserved specimens) profusely marked on the back, lateral fins and tail with 

 large spots of a dark purple-brown colour. In the young these spots are sur- 

 rounded by rather indefinite pale rings, which sometimes persist in the adult, 

 giving them an ocellate appearance. The posterior margins of the dorsal and 

 caudal fins are somewhat broadly, the anterior margins narrowly edged with white. 

 Ventral surface dead white, sometimes clouded with dark pigment in large 

 individuals. 



The mouth can be protruded as a depressed tube measuring, in the case of a large 

 individual, 35 mm. in length, 15 mm. in transverse diameter at the distal 

 extremity, and 8 mm. longitudinally. The teeth occupy about a third of each 

 jaw ; they have long, narrow, acutely pointed inner projections, which (in the 

 unworn tooth) are nearly as long as the transverse diameter of the bases. On 

 the roof of the mouth behind the teeth there is a pair of irregular, distinctly 

 separated, compressed vertical processes, and on the floor a similar pair ; in 

 both pairs the inner margins are emarginate on the basal half. The nasal flap 

 straight, very finely and shortly fringed, with a narrow, smooth stretch in the 

 middle. 



