270 THE PLAGIOSTOMIA. 



not produced into the snout. Snout elongate, pointed, formed by the long 

 rostral cartilage and a vascular area at each side of it. Nostrils oblique, anterior 

 valves not joined across the space between them, not reaching the mouth. Spir- 

 acles large, mostly with two folds on the hind margin, rarely with one or none. 

 Ventrals close to the pectorals. Dorsals behind the ventrals. Tail depressed, 

 robust anteriorly; caudal small, subcaudal portion weak and without a lobe. 



Mediterranean and African species. • . 

 Rhinobatus rhinobatus. 



Rhinobatus sive squatinoraia Columna, 1592, Phytob.; ed. 1744, p. 101, pi. 27; Willdqhby, 1086, 



Pise; Ray, 1713, Pise. p. 28. 

 Raia No. 1 Artedi, 1738, Ichthyologia, Syn., p. 99, Gen. p. 70. 

 Raia rhinobatos Linne, 1758, Syst., 1, p. 232; 1764, Mus. Adol. Frid., 2, p. 52; 1766, Syst., 1, p. 397; 



Gmelin, 1789, Linne Syst., 1, p. 1510 part; Gray, 1854, Gron. syst., p. 10. 

 Raia dorso dipterygio Gronow, 1763, Zoophy., 1, p. 36, no. 156. 

 Rhinobatus rhinobatos Klein, 1776, Neuer schaupl., 2, p. 593. 



Rhinobatus rhinobatus Schneider, 1801, Bloch Ichth., p. 353 (part); Cuv., 1817, Reg. anira., 2, p. 133. 

 Rhinobatus columnae Bonaparte, 1841, Icon. Fauna Ital., Pesci; Costa, 1854, Fauna reg. Nap., pesci, 



3, tav. 10; Gunth., 1870, Cat. fishes Brit, mus., 8, p. 446; Annandale, 1909, Mem. Ind. mus., 2, 



p. 14. 

 Rhinobatus (Syrrhina) columnae Muller & Henle, 1841, Plagios., p. 113; Dumeril, 1865, Elasm., 



p. 486. 



Width of disk little less than its length. Snout angle broad, about 65°, 

 end blunted, length less than twice the width of the mouth. Internarial space 

 narrower than the nostril, which latter is little more than half the width of the 

 mouth. Anterior nasal valve slightly extended inward from the edge; inner 

 section of posterior valve larger. Mouth nearly straight. Spiracle large, with 

 two prominent folds. Dorsals small, equal in base or in total length, anterior 

 taller, more pointed than those of R. lentiginosus, Plate 17, hinder margin slightly 

 concave. Scales very small. Small tubercles in a median series on the back, 

 in two groups on each shoulder, and in a row above each orbit. 



Back nearly uniform brownish, lighter to white at each side of the rostral 

 cartilage. 



Mediterranean Sea and Persian Gulf. 



Rhinobatus rasus. 



Plate 17a, fig. 1-2. 

 Rhinobatus rasus Garman, 1908, Bull. M. C. Z., 51, 253. 



Disk narrower and more pointed in front than that of R. rhinobatus; 

 crown flattened, edges of slight prominence; snout moderate, blunted, angle from 



