40 BULLETIN 189, UNITED STATES NATIONAL MUSEUM 



Genus SCOLIODON Miiller and Henle, 1837 



Body more or less compressed; head low, depressed; snout rather 

 long, moderately pointed; mouth greatly arched; lips with short 

 folds; teeth with broad bases with a rather high narrow cusp, the 

 lateral ones usually with an additional small posterior cusp, edges not 

 serrate ; nictitating membrane present; subcaudal lobe large. 



This genus is now for the first time reported from Peru. 



SCOUODON LONGURIO (Jordan and Gilbert) 



TOLLO; TOLLITO 



Carcharias longurio Jordan and Gilbert, 1882d, p. 106, Mazatldn, Mexico 

 (original description). 



Scoliodon longurio Jordan and Evermann, 1896, p. 42 (description). — Gilbert 

 and Starks, 1904, p. 12, Panama Bay. — Garman, 1913, p. 114 (descrip- 

 tion; range). — Meek and Hildebrand, 1923, p. 52, pi. 2, fig. 1, Panama 

 Bay (description). — Tortonese, 1939b, p. 198, pi. 5, fig. 1, Callao, Peru 

 (Synonymy; description). — Beebe and Tee-Van, 1941, p. 112, fig. 22, 

 (range; field characters; color; size; references). 



Body slender, its depth at origin of fu-st dorsal 6.0 to 6.4 in length 

 anterior to base of upper lobe of caudal; caudal peduncle only moder- 

 ately slender, its least depth 5.1 to 5.5 in head to first gill slit; head 

 much depressed, rather narrow, its depth over eyes less than width 

 of mouth by about half diameter of eye, its length to first gUl slit 

 3.5 to 3.75 in length anterior to base of upper lobe of caudal; snout 

 quite long, rather pointed, 2.3 in head, its preoral length exceeding 

 width of mouth by fully half diameter of eye, 2.5 in head; eye nearly 

 round, with vertically elongate pupU, 10.5 in head; mouth rather 

 narrow, its width at angles about equal to space between outer 

 margins of nostrils, 2.8 to 2.9 in head; labial folds well developed, 

 the upper one longer and broader than the lower, about a third the 

 length of the jaw to midline of snout; teeth anteriorly quite erect, 

 directed somewhat backward laterally, with a rather long narrow 

 cusp, and laterally with a low auxiliary cusp behind, sometimes 

 appearing merely as a broadened base, margins of teeth not serrate; 

 dermal denticles short and broad, with three prominent parallel 

 ridges, each extending beyond outer margin of denticle; fii'st dorsal 

 originating over beginning of distal thh-d of pectoral, its greatest 

 height generally somewhat exceeding width of head at eyes, its 

 distal margin concave, with a narrow produced posterior lobe; pre- 

 dorsal length 2.1 to 2.2 in length anterior to base of upper lobe of 

 caudal; distance between dorsal fins 2.9 to 3.1; second dorsal very 

 small, posteriorly produced, pointed, length of produced lobe about 

 1.5 times length of base of fin, origin of fin about over middle of base 

 of anal; upper lobe of caudal rather long, 3.15 to 3.6 in length anterior 

 to its base; lower lobe separated by a notch, exserted anteriorly; 

 anal similar to second dorsal, though somewhat longer, its base 4.6 



