180 MALACOPTERYGIT.—GINGLY MODI. 
Fam. 4. ELOPIDA. 
Two genera with five species, inhabiting tropical and subtropical seas. 
1. MEGALOPS, Lacep., 1803 *. 
Megalops, Giinth. Cat. Fish. vil. p. 471 (1868). 
Tarpon, Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1896, p. 409. 
Body elongate, compressed, covered with large silvery cycloid scales. Lateral line present. Head naked ; 
mouth large, terminal, the lower jaw prominent ; bands of villiform teeth in the jaws and on the palate 
and tongue. A gular plate between the rami of the lower jaw. Dorsal fin short, in the middle of the 
length of the fish, last ray produced; anal of moderate length ; caudal forked. 
Two species, one from the Indian Ocean, the other from the Atlantic coasts of 
America. 
1. Megalops atlanticus, Cuv. & Val., 1846. 
Megalops thrissoides (non Bl. Schn.), Giinth. Cat. Fish. vii. p. 472 (1868). 
Tarpon ailanticus, Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1896, p. 409, and 1900, fig. 117. 
Hab. Atlantic coasts of America from Long Island to Brazil, entering rivers. 
The Tarpon attains a length of 1800 mm. It has been recorded by Gill and 
Bransford (Proc. Ac. Philad. 1877, p. 187) from Lake Nicaragua. 
Sub-order IX. GINGLYMODI. 
This sub-order includes only the genus Lepidosteus, unique among fishes in having 
opisthocelous vertebre, and distinguished from other fresh-water fishes of Mexico 
and Central America by the rugose skull, the hard, rhombic ganoid scales, and the 
abbreviate heterocercal caudal fin. 
Fam, 1. LEPIDOSTEIDA. 
1. LEPIDOSTEUS, Lacep., 1803. 
Lepidosteus, Giinth. Cat. Fish. viii. p, 328 (1870); Jord. & Everm, Bull. U.S. Nat. Mus. xlvii. 
1896, p. 109. 
Body elongate, subcylindrical, covered with bony rhombic scales arranged in oblique series running downwards 
and backwards. Jaws elongate, the upper projecting beyond the lower; teeth conical, in the jaws and on 
the palate. Dorsal fin short, posterior, nearly opposite the anal ; pectorals placed low ; ventrals abdominal ; 
caudal rounded. 
Six or seven species of this genus may be regarded as valid. They inhabit North 
and Central America. 
* This name has been used for a genus of Staphylinide in the Biol. Centr.-Am. (Coleopt. i. pt. 2), but it has 
priority in Pisces. 
