CESTRACION ZVGAENA. 157 



concave on the hind border, lower and hinder angles produced. Caudal about 

 one third of the total length; subcaudal lobe produced. 



Total length l(i, snout to abdominal pores 7j, snout to fifth gill opening 3j, 

 snout to mouth lg, width of head 7j, snout to dorsal 4, and length of caudal 5g 

 inches. ( ircatest length of the lateral expansion l£, and greatest width from the 

 cheek 3 inches. 



Specimen described from Penang. 



East Indies and India. 



Cestracion zygaena. 



Plate 1, fig. 1-3. 



Libella Belon, 1553, Aquat., p. 61; Salviani, 1554, Aquat., f. 128, pi. 40. 



Zygaena Rondelet, 1554, Pise, p. 389; Gesner, 1558, Aquat., p. 1254; Aldrovandi, 1613, Pise. & cet., 



p. 408; Jonst., 1649, Pise, p. 29, pi. 7, f. 8; Willughby, 1686, Pise, pi. Bl. 

 Squalus sp. Artedi, 1738, Ichthyologia, Syn., p. 96, Gen., p. 67, no. 7; Gronow, 1754, Mus., 1, p. 63, no. 



139; 1763, Zoophy., p. 32, no. 146. 

 Cestracion sp. Klein, 1742, Hist, pise, miss. 3, p. 13. 

 Squalus zygaena Linne, 1758, Syst., 1, p. 234; Brunnich, 1768, Ichthy. Massiliensis, p. 4; Risso, 1810 



Ichth. Nice, p. 34; Mitch., 1815, N. Y. lit. & philos. trans., 1, p. 482; Gray, 1854, Gron. syst., p. 6. 

 Balance fish Brookes, 1763, Nat. hist., 3, Fishes, p. 31. 

 Cestracion zygaena Klein, 1776, Neuer schaupl., 3, p. 524, 706; Gill, 1862, Ann. N. Y. lye, 7, p. 403; 



Dumeril, 1865, Elasm., p. 382; Day, 1865, Fishes Malabar, p. 270. 

 he marleau Duhamel, 1777, Traite, 3, sect. 9, p. 303, pi. 21, f. 3-8; Broussonet, 1780, Mexn. Acad, roy., 



p. 661. 

 Le squale marteau Lacepede, 1798, Poissons, 1, p. 257. 

 Koma sorra Russell, 1S03, Coromandel fishes, 1, p. 8, pi. 12. 



Hammer-headed shark Shaw, 1804, Zool., 5, pt. 2, p. 46; Yarrell, 1839, Brit, fishes, suppl., p. 61. 

 Sphyrna zygaena Rafinesque, 1810, Ind. itt. Sic, p. 46; Muller & Henle, 1841, Plagios, p. 51; 



Bonaparte, 1841, Icon., Fauna ItaL, Pesci, Tav. 50, fig. 1; T. Cantor, 1849, Malay fishes, p. 



1383; Bleeker, 1852, Verh. Bat. gen. 24, Plagios., p. 42, pi, 3, f. 8; Bocage & Capello, 1866, 



Plagios., p. 17; Jord. & Everm., 1896, Bull. 47, U. S. nat. mus., p. 45. 

 Zygaena zygaena Cuv., 1817, Reg. anim., 2, p. 127; Gunther, 1810, Siidsee fische, 3, p. 434. 

 Zygaena malleus Valenciennes, 1822, Mem. Mus. hist, nat., 9, p. 223, pi. 11, f. 1; Risso, 1826, Hist. 



nat., 3, Poissons, p. 125; Jenyns, 1835, Man., p. 507; De Kay, 1842, N. Y. fish., p. 362, pi. 62, f. 



204; Schlegel, 1850, Jap. Pisces, p. 306, pi. 138; Storer, 1867, Mass. fish., p. 262, pi. 38, f. 3; 



GtiNTH., 1870, Cat. fishes Brit, mus., 8, p. 381; Day, 1878, Ind. fishes, p. 719, pi. 186, f. 4; Doder- 



lein, 1881, Man. ittiol. Medit., 2, p. 46; Moreau, 1881, Poiss. France, 1, p. 324; Day, 1884, Brit. 



fishes, 2, p. 294, pi. 154. 

 Sphyrichthys zygaena Thienemann, 1828, Lehrb., 3, p. 408. 

 Sphyrnias zygaena Gray, 1851, Chondropterygii, p. 49. 

 Sphyra malleus Hoeven, 1858, Handb., 2, p. 68. 

 Hammer-head Couch, 1867, Brit, fishes, 1, p. 70, pi. 16. 



Front margin of the head a broad irregular curve which may be included in 

 the segment of a circle with a radius from the fifth gill openings, but not con- 

 tinuous with the lateral edges of the hammer. Width of hammer, oculonarial 

 expansion, on the hind margin nearly equal to its length across the end at the eye. 

 A rather deep concave notch above the nostril, which latter has a groove on the 

 front margin, more than half the distance to the middle of the snout. Orbit 



