160 THE PLAGIOSTOMIA. 



Greyish brown, head darker, fins darker with light margins. Described 

 from specimens taken at Rio Janeiro and Panama. 

 Tropical Seas. 



Cestracion mokarran. 



Zygaena mokarran Ruppell. 1835, Neue wirb. Abyssinien, fische, p. 66, pi. 17, f. 3; GDnth., 1870, Cat. 



fishes Brit, mus., 8, p. 383; Day, 1887, Ann. mag. nat. hist., ser. 5, 20, p. 389; 1888, Ind. fishes, 



suppl., p. 809. 

 Sphyrna mokarran Muller & Henle, 1841, Plagios, p. 54. 

 Sphyrnias mokarran Gray, 1851, Chondropterygii, p. 51. 

 Cestracion {Zygaena) mokarran Dum^ril, 1865, Elasm., p. 383. 

 Zygaena dissimilis Murray, 1887, Ann. & mag. nat. hist., ser. 5, 20, p. 304. 



Width of head one fourth less than the length of the caudal. Oculonarial 

 expansions at the sides of the head nearly at right angles with the longitudinal 

 axis of the body; anterior margin of the head nearly straight. Nostrils near the 

 eye, without a notch above them, without a groove from their inner edges. Teeth 

 triangular, oblique, with fine serrations on the edges; upper broader, notched on 

 the outer edge; lower with the cusp more erect and slender, with an indentation 

 on both outer and inner edges. Hindmost two of the gill openings above' the 

 pectoral. All fin angles rather sharp; first dorsal higher than long, origin above 

 the end of the pectoral base, at about one fourth of the length from the snout to 

 the end of the tail, base equal half the height on the front margin. Ventrals in 

 front of the mid length. Second dorsal and anal nearly equal, similar in shapes; 

 anal origin slightly behind that of the dorsal; hind margins deeply indented. 

 Reaching a length of more than ten feet. 



Dingy bluish gray or brown, lighter to whitish or flesh color below. 



Red Sea; India. 



Cestracion tiburo. 

 Plate 1, fig. 4-5. 



Tiburonis species minor Marcgrave, 1648, Hist. nat. Brasil , p. 181, fig. 



Zygaenae aijinis capite triangulo Willughby, 1686, Hist, pise, p. 55, pi. B9, f. 3. 



Cestracion no. 2 Klein, 1742, Hist, pise, miss., 3, p. 13, pi. 2, f . 3, 4. 



Squalus tiburo Linnte, 1758, Syst., 1, p. 234; 1766, Syst., 1, p. 399; Bonnaterre, 1788, Ichth., p. 9; 



Gmelin, 1789, Linn6 Syst., 1, p. 1495; Shaw, 1795, Nat. misc., 7, pi. 229; Schn., 1801, Bloch 



Ichth., p. 131. 

 Cestracion tiburo Klein, 1776, Neuer schaupl., 3, p. 526; Gill, 1861, Proc. Acad. nat. sci. Phil., p. 59 



extra; Dum^ril, 1865, Elasm., p. 385. 

 Le pantouflier Broussonet, 1780, M6m. Acad roy., p. 662. 

 Round-headed Zygaena Shaw, 1795, Nat. misc., 7, pi. 229 

 Heart-headed shark Shaw, 1804, Zool., 5, p. 355, pi. 154. 

 Sphyrna tiburo Rafinesque, 1810, Ind. Sic, p. 47; MtJLLER & Henle, 1841, Plagios., p. 53; Gilbert & 



Starks, 1903, Mem. Cal. acad. sci., 4, p. 13. 

 Cestrorhinus tiburo Blainv., 1816, Bull. See. philom., p. 121. 



