144 



Memoirs of the Indian Museum. 



[Vol.. II, 



proportions of eye and spiracle it differs from the others, which resemble one another 

 in this respect. All three specimens are of the same colour and have the same char- 

 acteristic ocellus at the base of the pectoral fin. 



The shape of the teeth is alike in the three specimens ; the same may be said of 

 the form and disposition of the dorsal and caudal fins. 



A. B. C. 



Fig. I.— Mouths of Rata: A. = R. powelli ; B. = Raia sp. ; C. = R. philipi. 



Family TORPEDINID^. 



Narcine mollis, Lloyd. 



Lloyd, Rec. Ind. Mus., vol. i, p. 8 (1907); Annandale, Mem. Ind. Mus., vol. ii, no. i, 

 p. 43, pi. iiia, figs. 3, 3a. 



Illustr. Zool. " Investigator," Fishes, pi. xlvi, figs, i, la (1909). 



The vent is slightly nearer the anterior margin of the snout than the tip of the 

 tail. The disk is evenly rounded , it is slightly broader than long. The margin of the 

 flap formed by the confluent nasal valves is most prominent at the sides, unlike 

 AT", timlei, the other Indian species. The whole quadrangular space which lies between 

 the two nasal clefts is nearly as long as it is broad. In N . timlei this space is three 

 times as broad as it is long. 



The anterior dorsal is slightly smaller than the posterior; it commences just 

 behind the ventrals. The dorsal and caudal fins have blunt pointed ends and the 

 folds of skin along the sides of the tail are obvious, but not prominent. The dorsal 

 and ventral parts of the caudal fin are confluent. 



The teeth are in 10 to 12 rows in both jaws ; the front row has only 3 or 4 teeth ; 

 behind this the number gradually increases in succeeding rows up to about 16. The 

 teeth of the front rows have triangular, flat surfaces ; behind, the teeth bear a sharp 

 median cusp. 



The spiracle is immediately behind the eye and is the same size as the eye. 



The electric organs seem well developed. The fish gave no perceptible shock to 

 the hand and died soon after capture. 



Round the margin of the disk, and along the sides of the tail, and over the snout, 

 are the openings of mucous pores symmetrically arranged. 



