HAMMERHEAD SHARKS — GILBERT 



53 



ton. (Texas): USNM 82710 (2), Chame Point Pass; USNM 116450 

 (5), MCZ 35824-35825 (2), MCZ 36157 (1), MCZ 36240-36245 (9), 

 Galveston; USNM 127101 (1), USNM 155964 (18), Corpus Christi; 

 USNM 127104 (1), Harbor Island; USNM 127106 (1), Parateria 

 I (Grand Pass) ; USNM 127109 (1), ca. 13 mi. off Bay Chalaud; FMNH 

 I 37794-37796 (3), Port Aransas, Aransas; FMNH 11195-11198 (4), 

 Laguna Madre, Point Isabel. (Virginia): USNM 125760 (1), Lynn- 

 haven Koads, just west of Cape Henry light; MCZ 138 (skin), 

 I Hampton Roads; FMNH 1622 (1), Ocean View. 



Figure 12. — Sphyrna tiburo: a, head of S. t. vespertina, a specimen 636 mm. TL (UCLA 

 58-46), from Gulf of California, showing pointed head; h, head of S. t. tiburo, a specimen 

 637 mm. TL (USNM 57242), from southern Florida, showing rounded head; c, head of 

 S. /. tiburo, a specimen 880 mm. TL (USNM 127106), from Texas, showing intermediate 

 condition of head. (Drawings by Dorothea B. Schultz.) 



Diagnosis. — Sphyrna tiburo tiburo differs from S. tiburo vespertina 

 in having a slightly narrower and more evenly rounded head. These 

 differences are illustrated in figures 12 and 13. 



Sphyrna (Platysqualus) tiburo vespertina Springer 



Figure 12a; Plate 7b 



Sphyrna vespertina Springer, 1940a, pp. 161, 164-166. (Original description; com- 

 parisons; range; holotype, a 769 mm. female, SU 11584; type locality, Panama 

 City; paratypes, a 520 mm. female, SU 11881, same locality as holotype; and 

 a 938 mm. male, formerly Carnegie Museum no. 5675, from Guayaquil, 

 Ecuador.) 



Specimens examined. — (Range in size: 277-880 mm. TL). Ec- 

 uador: USNM 88677 (1), FMNH 59350 (1), Guayaquil. El Sal- 

 vador: USNM 21627 (1), Acajutla. Mexico: USNM 190595 (1), 

 Camorore Beach, ca. 3 mi. north of Mazatlan, Sinaloa; UCLA 51-4 

 (1), Gulf of California, Bocochibampo Bay, Sonora; UCLA 52-250 

 (4), Almejas Bay, at anchorage off Santa Margarita Island, Baja 

 California; UCLA 58-46 (1), Gulf of CaUfornia, south of Bahia Top- 

 olobampo, off Isla San Ignacio and Isla Macapule, Sinaloa; CAS (W 

 55-167) (1), Gulf of California, south end of Angel de la Guarda 

 Island; CAS 3987 (1), Guaymas; SIC 47-53 (1), Gulf of California, 15 



