130 THE PLAGIOSTOMIA. 



Carcharinus velox. 



Carcharinus velox Jordan & Everman, 1898, Bull. 47, U. S. nat. mus., p. 2747. 

 Carcharias velox Gilbert & Starks, 1903, Mem. Cal. acad. sci., 4, p. 9, pi. 1, f. 3. 



Head long, one fourth of the total, rather narrow and pointed, depressed. 

 Snout elongate, about two fifths of the head, including the gill openings. Nostrils 

 in the middle of the preoral length, width equal that of orbits or the distance 

 from the eye, narial valve without a pointed lobe. Mouth large, much arched, 

 width less than length of snout, length two thirds; labial fold a short groove on 

 the upper jaw at the angle, directed out and forward. Upper teeth subtriangular, 

 oblique, deeply notched on the outer edge, serrated; lower broad based with 

 narrow cusps and fine serrations visible under a lens. Pectorals subfalciform, 

 width hardly two thirds of the length, pointed, reaching behind the base of the 

 dorsal, hind margin deeply concave, inner extremity somewhat produced, rounded 

 on the angle. First dorsal nearer to the pectoral than to the anal, origin at a 

 little distance behind the base of the pectoral, hind margin deeply excavated, 

 angle produced, base about two fifths of its distance from the second dorsal. 

 Second dorsal directly opposite the anal but smaller, origin slightly farther back, 

 hind margin nearly straight. Anal little larger than second dorsal, hind margin 

 deeply indented. Caudal more than one fourth of the total, pointed, greatest 

 depth less than half the caudal length; subcaudal lobe produced, blunted. 



Greyish brown; white below. 



Panama. 



Carcharinus obscurus. 



Squalus obscurus Lesueur, 1818, Journ. Acad. nat. sci. Phil., 1, p. 223, pi. 9; Gill, 1861, Proc. Acad., 



nat. sci. Phil., p. 59 extra, 

 Carcharias falcipinnis Lowe, 1839, Proc. Zool. soc. Lond., p. 90; 1843, ibid., p. 93; 1843, Trans. 



Zool. soc. Lond., 3, p. is. 

 Carcharias (Prionodon) obscurus Muller & Henle, 1841, Plagios., p. 40; Dumeril, 1805, Elasm. 



p. 371 ; Gunth., 1870, Cat. fishes Brit . mus., 8, p. 360. 

 Carcharias obscurus DeKav. 1842, X. V. fish., p. 350, pi. 61, f. 201; Storer, 1867, Mass. fish., p. 243, 



pi. 36, f. 2. 

 Prionodon obvelatus Valenciennes, 1S43, Ichth. Canar., p. 103, pi. 26; Dumeril, 1865, Elasm., p. 376. 

 Platypodon obscurus Gill, 1864, Proc. Acad. nat. sci. Phil., p. 262. 

 Carcharinus obscurus Jord. & Gilbert, 1883, Bull. 16, U. S. nat. mus., p. 22. 

 Carcharinus (Platypodon) obscurus Jord. & Kverm., 1896, Bull. 47, U. S. nat. mus., p. 35. 



Body moderately stout and long, the cavity extending slightly behind the 

 mid length. Head depressed, much broader than deep; crown convex; snout 

 broad, broadly rounded in front of the nostrils. Outer angle of nostril nearer 

 to the eye than to the end of the snout. Eye small, hardly one third of the oral 

 length. Mouth large, width greater than the preoral length, length three fifths 



