68 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 119 



inner corner of pectoral fin narrowly rounded; length of pelvic fin 

 from two-thirds to nine-tenths length of anal fin; length of pelvic fin 

 base from five-ninths to seven-eighths length of anal fin base; anterior 

 and distal margins of pelvic fin nearly straight; anal fin from one- 

 eighth to one-third again as long as pelvic fin; length of anal fin base 

 from one-third to one-half again as long as pectoral and pelvic fin 

 bases and about twice as long as second dorsal fin base; height of 



> S 



d 



f 



Figure 21. — Appearance of upper precaudal pit: a, Sphyrna blochii, 615 mm. female, from 

 North Borneo (FMNH 21836); b, S. mokarran, 675 mm. male, from Florida (USNM 

 106543); c, S. zy gaena, 580 mm. male, from Virginia (USNM 119699); d, S. lewini, 495 

 mm. female, from Texas; e, S. t. tiburo, 880 mm. female, from Texas (USNM 127106); 

 /, S. media, 900 mm. female, from Panama Bay (UCLA 58-304); g, S. viedia, 356 mm. 

 female, from Chiapas (FMNH 63093); h, S. corona, 371 mm. male, from Chiapas (FMNH 

 72521, ex, 63093); i, S. tudes, 825 mm. male, from Surinam (USNM 156721). (Figs, a-f, 

 i drawn by Dorothea B. Schultz; figs, g, h by Paul Laessle.) 



anal fin from one-fifth to one-third greater than height of second 

 dorsal fin; anal fin deeply falcate toward apex, nearly straight toward 

 tip of lobe; length of caudal fin nearly a third of total body length; 

 upper margin of caudal fin slightly convex; terminal part of caudal 

 about one-fourth of total length of fin; lower posterior margin of 

 terminal part of caudal fin nearly straight or slightly falcate; both 

 terminal and lower apices of caudal broadly pointed; lower lobe of 



