RHINOBATUS. 2G9 



the disk, pointed, angled near 45° on a specimen of nineteen inches. Crown 

 transversely convex in the middle, concave toward each edge, width less than one 

 third length of snout. Mouth arched in the middle, with larger teeth on the 

 arches, in 63 rows on the upper jaw of a specimen nearly six feet in length. 

 Labial folds and cartilages well developed (Plate 65, fig. 1, I). Nostrils wide, 

 oblique, narrower and curved back toward the mouth on inner ends, three fourths 

 as wide as the mouth; valves feebly developed, nearly half the width of the 

 nostril, anterior with a short rounded lobe and an inner section reaching one 

 third of the distance from the lobe to the inner angle of the nostril, posterior 

 with the outer section and the elongate lobe continuous and the inner. section 

 narrow and short. Internarial space not as wide as the nostril. Spiracle as 

 large as the eye and close to it, with two folds. Pectorals small, not extended 

 opposite the nostrils. Dorsals moderate, angles produced, hind margins deeply 

 concave; base of the first dorsal more than its length behind the axil of the 

 pectoral, origin little behind origins of ventrals, second dorsal nearly three times 

 the length of its base behind that of the first. 



Ventrals small, narrow, hind angle produced, bases more than their length 

 behind those of the pectorals. Tail depressed continuous in width with bod}^ 

 from the pectorals, with a narrow dermal keel at each side; caudal axis slightly 

 raised, supracaudal pointed, subcaudal lobe prominent. A series of small 

 tubercles above the vertebrae, two short series on each shoulder, inner larger 

 and preceded at a short distance by another series of half a dozen on the nape, 

 and a row on the orbital ridge, interrupted above the spiracle. 



Young greyish to olive or brown with small spots of white more or less sym- 

 metrically placed on body and tail and surrounding a black spot, or in cases a 

 ring with a Ught centre, as large as the spiracle, above each end of the shoulder 

 girdle. Large individuals are uniform greyish brown. 



Red Sea to East Indies, Africa to India. 



Rhinobatus. 



'Pi»'6/?aTos Aristotle, HEPI znnN ISTOPIAS to F, XI. 



Rhinobates Jovius, 1524, Romanis Piscibus, c. 29. 



Rhinobatos Wotton, 1552, Diff. anim., p. 144G; Salvia.ni, 1554, Aquat., f. 153. 



Rhinobatus Rondelet, 1554, Pise, p. 370; Gesner, 1558, Aquat., p. 1084; Klein, 1742, Hist, pise, 



miss., 3, p. 32; 1749, ibid, 5, p. 78; 1776, Neuer schaupl., 2, p. 592; Link, 1790, Lichtenberg & 



Voigt's mag., 6, stuck 3, p. 32; Walbaum, 1792, Aitedi, p. 581. 



Disk subtriangular, wider and rounded posteriorly; pectorals rather nar- 

 row, most developed behind the shoulder girdle, narrowing to acute forward, 



