64 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 119 



imum size as S. media, because the largest specimen examined (672 

 mm.) was little over half as large as the largest specimen of S. media 

 that was seen. 



A comparison of Sphyrna corona with other members of the genus 

 is presented in table 1. 



Description. — Since most of the morphological characters in 

 Sphyrna corona are similar to those found in S. media, the following 

 description has been condensed so as to avoid repetition. Only those 



]Map 5. — Distribution of species. 

 O sphyrna tudes A Sphyrna media 



V sphyrna corona 

 ^ Sphyrna media and Sphyrna corona 

 (Solid = specimens examined; hollow = 

 confirmed literature references.) 



wmm 



characters in which actual counts or measurements are cited are 

 listed in the following account. For other characters see either the 

 diagnoses of S. corona or the subgenus Platysgualus, or the description 

 of *S'. media. 



Meristic data appear in table 8. 



Head moderately expanded, the greatest width measuring from 



13— ?— 13 

 23.7 to 29.1 percent of TL; teeth ' ' (count given for holotype 



1^—1 — lo 



by Sprmger, 1940a, p. 163) ^^_~_.^^ and j^z^' 



Range. — Sphyrna corona has one of the most restricted ranges of any 

 species of hammerhead, occurring only in the eastern Pacific from 

 southern Mexico south at least to the coast of Colombia (map 5). 



Sphyrna (Platysqualus) tudes (Valenciennes) 



Figures 19, 20, 21z, 22h; Plates 4, 8 



Zygaena tudes Valenciennes, 1822, pp. 225-226. (Illustration of head; original 



description [apparently based on two species, S. tudes and *S. 7nokarran]; 



types from Nice and Cayenne are S. tudes, as here recognized, while type 



from Coromandel probably is S. mokarran.) 

 Sphyrna tudes Mi'iUer and Henle, 1841, p. 53. (In part; identification by reference 



to Valenciennes, 1822.) 

 Sphyrna bigelowi Springer, 1944, pp. 274-276. (Original description; illustration; 



type locality, Uruguay ; holotype, a 385 mm. male [USNM 87682]; paratypes, 



a 395 mm. male from Uruguay [USNM 120751], and a 900 mm. female 



from Rio de Janeiro, Brazil [MCZ 463].) 

 Specimens examined. — (Range in size: 213-900 mm. TL). West- 

 ern Atlantic Ocean (including Caribbean Sea and Gulf of Mexico): 



