42 o Memoir Sears Foundation for Marine Research 



Ittiol. Medit., 2, 1881: 46 {malleus Valenciennes, incl. in synon.) ; not Squdus malleus Shaw and 

 Nodder, 1796. 



Sfhyritias zygaena (in part) Gray, List Fish. Brit. Mus., 1 851: 48 {malleus Valenciennes, incl. in synon.) ; 

 White, List Spec. Brit. Mus., Fish., 8, 1851: 126 {malleus Valenciennes, incl. in synon.). 



Sfhyrna zygaena (in part) Ribeiro, Arch. Mus. nac. Rio de J., 14, 1 907: 202 {malleus Valenciennes, incl. in 

 synon.); Nichols and Murphy, Brooklyn Mus. Sci. Bull., 3 (l), 1916: 19 (ill. shows diflana shape of 

 head, no loc, but discussion refers to zygaena) ; Springer, Proc. Fla. Acad. Sci., 5, 1939: 31 (combined 

 with zygaena in descr., habits, ident. by shape of head in ill., Florida) ; Fowler, Bull. U.S. nat. Mus., lOO 

 {23), 1941: 217 (OTa//i!a/ Valenciennes, incl. in synon.). 



Cestracion zygaena (in part) Garman, Mem. Harv. Mus. comp. Zool., 36, 1913: 157 {malleus Valenciennes, 

 incl. in synon.) ; Radcliffe, Bull. U.S. Bur. Fish., 34, 1916: 263, pi. 43, fig. I (N. Carolina spec, ident. 

 by ill. of head) ; Meek and Hildebrand, Field Mus. Publ. Zool., 15 (1), 1923: 58 {malleus Valenciennes, 

 incl. in synon.; ident. of spec, from Colon, whether diflana or zygaena, not certain from descr.); not 

 Squalus zygaena \Jmniitxis, 1758. 



Hammerhead Shark, Smith, J. Amer. Mus. nat. Hist., 16, igi6: 348 (photo of lo-foot spec, descr. as Cestra- 

 cion zygaena by Welsh, 1 91 6). 



Cestracion zygaena Welsh, Copeia, 38, 1 916: 94 (meas. of spec, shown in photo by Smith, 1 916, as above; 

 90 miles off C. May, N. Jersey) ; not Squalus zygaena Linnaeus, 1758. 



Sfhyrna diflana Springer, Proc. Fla. Acad. Sci., 5, 1 941: 46 (descr., ill., discuss., both coasts of Florida, 

 Mississippi, Louisiana, Texas, trop. W. Afr., and probably Medit.) ; Bigelow and Schroeder, Guide 

 Comm. Shark Fish., Anglo Amer. Caribb. Comm., Wash., 1945: 136, fig. 50 (descr., range, ill.). 



Doubtful References: 



Sfhyrna tudes Ribeiro, Arch. Mus. nac. Rio de J., 14, 1907: 157, pi. 5 (ident. probable because of shape of 



head in photo, Maria Farinha, near Pernambuco, Brazil); Fauna brasil. Peixes, 2 (i) Fasc. I, 1923: 14 



(same as foregoing) ; not Zygaena tudes Valenciennes, 1822. 

 Sfhyrna tiburo (in part) Puyo, Bull. Soc. Hist. nat. Toulouse, yo, 1936: 82 (head ill. of diflana shape, but 



discuss, apparently of tiburo); not Squalus tiburo Linnaeus, 1 75 8. 



Sfhyrna tiburo (Linnaeus), 1758 



Bonnet Shark, Shovel Head 



Figure 82 



Study Material. Seventy-one specimens, embryos to adults, 217 to 1,090 mm. long, 

 including one female containing eight young nearly ready for birth and another with nine, 

 from: Hampton Roads, Virginia} Charleston, South Carolina; Tortugas, Florida; Barra- 

 taria Bay and Bayou Fifi, Louisiana; Galveston, Corpus Christi and Harbor Island, Texas; 

 Cuba; Bahia, Pernambuco, Rio Parahyba and Rio de Janeiro, Brazil; also, from Pacific 

 coast of Panama and San Diego, California (Harv. Mus. Comp. Zool. and U.S. Nat. 

 Mus.). Also, paratypes of 5. ves-pertina Springer, Pacific Panama, loaned by the Carnegie 

 Museum of Pittsburgh and Stanford University, California. 



Distinctive Characters. Tiburo is most obviously marked oflF from diflana, bigelowi, 

 tudes and zygaena in having a shovel- (not hammer-) shaped head not indented margin- 

 ally opposite the nostrils; also, the outermost 4 or 5 teeth in the lower jaw are evenly 

 rounded, without cusps or a definite cutting edge. It is separated from bigeloim, diflana 



