CESTRACION ZYGAENA. 157 



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

 one third of the total length; subcaudal lobe produced. 



Total length 16, snout to abdominal pores 7l, snout to fifth gill opening 3j, 

 snout to mouth l|, width of head 7^, snout to dorsal 4, and length of caudal 65 

 inches. Greatest length of the lateral expansion ll, 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 RoNDEhET, 1554, Pise, p. 389; Gesner, 1558, Aquat., p. 1254; Aldkovandi, 1613, Pise. & cet., 



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

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



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

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

 S(iualus zygaena Linn^, 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. 

 Le marteau Duhamel, 1777, Traite, 3, sect. 9, p. 303, pi. 21, f. 3-8; Broussonet, 1780, M6m. Acad, roy., 



p. 661. 

 Le squale marleau Lac^p^ide, 1798, Poissons, 1, p. 257. 

 Ko7na sorra Russell, 1803, 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 Rafinesqtje, 1810, Ind. itt. Sic, p. 46; MtJLLER & 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 Cvv., 1817, Reg. anim., 2, p. 127; GtJNTHER, 1810, Sudsee 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; 



GtJNTH., 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 tnalleus 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 wliich 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 



