APHIOXODON ISO DON. 119 



angle of the pectoral, acuminate hinder extremity reaching slightly backward 

 of the origins of the ventrals, end of base about twice the length of the orbit 

 farther forward, hind margin concave. Second dorsal smaller than the first, 

 larger than the anal, less than twice the base farther back than that of the first 

 dorsal, hind margin deeply indented. Anal smaller than second dorsal, little 

 more excavated on the hind margin; base opposite the middle of that of the 

 second dorsal and about three fourths of the length, distance from the caudal 

 about equal. Caudal medium, less than one fourth of the total, lower lobe not 

 much produced. 



Ashy or greyish brown, edges of hindmost fins blackish; lower surfaces 

 lighter. 



Total length 34, snout to abdominal pores 18, snout to fifth gill opening 7\, 

 snout to mouth 2, and caudal 8j inches. 



Approaches toward the genus Triaenodon appear in the positions and 

 relative proportions of the fins, and in a notch at each side of the cusp on the 

 bases of the upper teeth. 



Indian Ocean and Archipelago ; Red Sea. Specimen described from Apiang, 

 taken by Andrew Garrett. 



Aprionodon isodon. 



Carcharias (Aprion) isodon Muller & Henle, 1841, Plagios., p. 32. 



Aprionodon punclalus Gill, 1861, Ann. N. Y. lye, 7, p. 401; Jordan & Gilbert, 1883, Bull. 16, U. S. 



nat. mus., p. 24. 

 Carcharias (Aprionodon) isodon Dumeril, 1865, Elasm., p. 349. 

 Carcharias (Aprionodon) punctalus Gunth., 1870, Cat. fishes Brit, mus., 8, p. 361. 

 Aprionodon isodon Poey, 1876, An. Soc. Esp. hist, nat., 5, p. 200; Jord. & Everm., 1896, Bull. 47, U. S. 



nat. mus., p. 42. 



Snout much shorter than that of A. brevipinna, blunt, distance from the 

 angle of the mouth to the nostril twice that from the nostril to the end of the 

 snout, preoral length equal the distance between the nostrils. Width of nostrils 

 hardly less than length of orbits. Teeth erect, without serrations, in fi rows; 

 upper small with broad bases; lower similar but smaller; median teeth small. 

 Pectorals subfalciform, reaching the hind end of the base of the first dorsal. 

 Second dorsal much smaller than the first, above the anal. The pectorals in this 

 species are larger comparatively than those of A. brevipinna; in positions and 

 forms of the other fins the two are alike. Originally described from a specimen, 

 about two feet in length, said to have been collected at New York. 



Western Atlantic. 



