4IO 



Memoir Sears Foundation for Marine Research 



3b. Free tip of 2nd dorsal considerably longer than its vertical height, and at least 



as long as its anterior margin; teeth with smooth-edged cusps, serrated only on 



basal expansions, if at all. 



4a. Center of eye opposite or posterior to front of mouth; corner of mouth an- 

 terior to outer posterior corner of head (hammer) ; posterior margin of anal 

 fin deeply concave. diplana Springer, 1941, p. 415. 



4b. Center of eye considerably anterior to front of mouth ; corner of mouth con- 

 siderably posterior to outer posterior corner of head (hammer) ; rear mar- 

 gin of anal only weakly concave. bigelowi Springer, 1944, p. 410. 



Sfhyrna bigelowi Springer, 1 944 

 Figures 79, 80 



Study Material. Immature male, about 886 mm. long, from Rio de Janeiro, Brazil 

 (Harv. Mus. Comp. Zool., No. 463) ; young male, about 385 mm., from Uruguay (U.S. 

 Nat. Mus., type, No. 87682). 



Distinctive Characters. This newly discovered species falls with diplana and tudes 



Figure 79. Sfhyrna bigelowi, immature male, about 886 mm. long, from Rio de Janeiro, Brazil (Harv. Mus. 

 Comp. Zool., No. 463). A Dermal denticles, about 22 x. 5 Dermal denticle, side view, about 44 x. C Dermal 

 denticle, apical view, about 44 x. D Upper and lower teeth, left-hand side, about 2 x. E Fifth upper tooth. 

 F Twelfth upper tooth. G Fifth lower tooth. H Twelfth lower tooth. E-H, about 4 x. 



