66 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 119 



A comparison of Sphyrna tudes with other members of the genus is 

 presented in table 1. 



Description. — Meristic data appear in table 9. Characters men- 

 tioned in the diagnoses of the subgenus Platysqualus and of S. tudes 

 are not repeated here. 



Head moderately expanded, the greatest width measuring from 

 27.5 to 31.5 percent of TL; inner narial gTOOve extending 3.5 to 4.0 

 percent of distance from narial openings to median notch; outer 

 posterior corner of lateral expansion of head situated posterior to 



UMJJJU'.Ar^ 



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Figure 19. — Sphyrna tudes: a, subadult male, 886 mm. TL, from Rio de Janeiro, Brazil 

 (MCZ 463); h, upper and lower teeth, left side, of same specimen, about L5 X; c, fifth 

 upper tooth; d, twelfth upper tooth; e, fifth lower tooth;/, twelfth lower tooth; g, dermal 

 denticles of MCZ 463, about 17 X ; A, dermal denticle, side view, about 34 X ; i, dermal 

 denticle, apical view, about 34 X. {c-f, about 3 X.) (From Bigelow and Schroeder, 

 1948, p. 410.) 



corner of mouth in smaller specimens, anterior to corner of mouth in 

 larger individuals; narial flap rather narrow (particularly in smaller 

 specimens), pointed at tip, with the broadly curved outer edge curving 

 sharply inward; length of snout about two-fifths of head width in 

 smaller specimens to about one- third of head width in larger speci- 

 mens; greatest transverse distance between corners of mouth from 

 one-fifth to one-fourth of greatest width of head; a very short labial 

 furrow present at corner of lower jaw in larger specimens, not notice- 

 able in smaller specimens. 



Origin of first dorsal fin slightly posterior to axil of pectoral fin, 

 a perpendicular line drawn ventrally from origin intersecting anterior 



