444 BHINOB.VTID^. 



about two-thirds of that between the mouth and the end of the 

 snout. Mouth straight. Back covered with very distinct rough 

 scales, which become hirgcr towards the median line of the back, 

 there not being a median series of tubercles. No distinct spines at 

 the eye and shoulder. The two rostral ridges much divergent be- 

 hind, and confluent in the anterior third of their length. 



Etust Indies. 

 a. Stuffed, 30 inches long. East Indies. Purchased of Mr, Argent, 



5, Rhinobatus undulatus. 

 Puraque, Marcf/r. p. lol (cop. by WUhujhhy, p. 80, tab. D 5. fig. 2) ; 



Jonstun, De Pise. p. 201, tab. JJG. fig. 9. 

 Rhinobatus electricus, Bl. Sc/tn. p. 3oG. 

 undulatus, Olfers, Torped. p. 22 ; Mull. Sf Hcnle, p. 121, pi. 40 ; 



Cnsteln. An. Am. ISud, Poiss. p. 100; Diimeril, Elasmobr. p. 498; 



Kner, Novara, Fkch. p. 417. 



glaucostictus, Olfers, I. c. 



marcgravii, Henic, Narcin. p. 34. 



Anterior nasal valve dilated into a very narrow lateral fold, 

 scarcely extending beyond the nasal margin*. Snout i)roduced, the 

 distance between the outer angles of the nostrils being rather more 

 than one-half of that between the mouth and the end of the snout. 

 Mouth straight. Back minutely granular, nearly smooth, with a 

 senes of small, polished, depressed spines along the median line ; 

 similar spines on the orbital margin and on the shoulder. The two 

 rostral ridges are narrow, and separated by a very narrow groove in 

 their entire length. 



South America ; Mediterranean (?). 



a. Stuffed, 20 inches long. Mediterranean (?). 



b. Half-grown. Bahia. From Dr. Wuchcrer's Collection, 



Rhinobatus horlcelii (Miill. & Henle, p. 122, pi. 41 ; Casteln. An. 

 Am. Sud, Poiss. p. 100 ; Dumeril, Elasmobr. p. 499), from Bahia, 

 appears to be most closely allied to lih. undulatus ; but it has not a 

 white snout like this latter species. 



I am also inclined to regard Rhinobatus cemiculus (Geoifr. St.-Hil. 

 Dcscr. Eg. Poiss. p. 224, pi, 27. fig. 3 ; Miill. & Henle, p. 118 ; Uu- 

 ineril, Elasmobr. p. 495), from the ^[cditerranean (and the lied 

 Sea?), as identical with Rh. undulatus, as the difference in the 

 distance of the nostril from the lateral profile of the snout is not a 

 reliable character, 



6. Rhinobatus leiicorhynchus. 



G'unth. Proc. Zool. Sac. 1800, p. 004, and Trans. Zool. Soc. 18C8, 

 p. 490. 



Anterior nasal valve dilated into a very narrow lateral fold, 

 scarcely extending beyond the nasal margin. Length of the nos- 

 tril more than its distance from the outer profile of the head, or 

 * First approach to Syrrhina. 



