74 HAPLOMI. 
There are examples of the former species, collected by Herr Forrer at Presidio, in the 
British Museum collection. Atlantic coast species are P. virginicus, Linn., and 
P. octonemus, Girard, the former usually with 7 pectoral filaments, the latter usually 
with 8. 
Sub-order IV. HAPLOMI. 
The Haplomi are represented in the fresh waters of Mexico and Central America by 
two families, Scombresocide and Cyprinodontide, which may be distinguished from 
other soft-rayed fishes with abdominal ventral fins by the following combination of 
characters :—‘ Jaws toothed; premaxillaries wholly or in great part excluding the 
maxillaries from the upper border of the mouth. Gill-membranes free from the 
isthmus. Body scaly; lateral line either absent or placed very low. Fins without 
spinous rays; a single dorsal; no adipose fin; ventral fins, if present, 5- to 7-rayed, 
abdominal in position.” 
The two families may be distinguished thus :— 
Lateral line present, running along the edge of the lower surface of the 
body . 2... ew ee ee ee ee ee ee .) O ScomBRESOCIDE. 
No laterallme . 2. 2. 1. 2. 1 ew eee ee we we OR, C¥PRINODONTIDE. 
Fam. 1. SCOMBRESOCIDA. 
The Scombresocide are marine Fishes of the tropical and temperate seas. Some of 
the species of Belone and Hemirhamphus enter rivers, and a few permanently fluviatile 
forms are now usually referred to distinct genera. 
1. BELONE, Cuv., 1817. 
Belone, Giinth. Cat. Fish. vi. p. 234 (1866). 
Tylosurus (Cocco), Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1896, p. 708. 
Body slender, elongate. Mouth with wide lateral cleft, both jaws being much prolonged ; jaws with small 
pointed teeth in bands and with a series of enlarged, wide-set, conical teeth; palate toothless. Scales 
small. Dorsal and anal fins opposite each other and posterior in position; caudal lunate or forked ; 
pectorals asymmetrical, placed high ; ventrals 6-rayed, inserted posteriorly. 
Many species from tropical and temperate seas; of eighteen American forms, two 
have been recorded from fresh-water localities in Mexico and Central America. 
1. Belone marina, Walbaum, 1792. 
Tylosurus marinus, Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1896, p. 714; Meek, Publ. Columbian 
Mus., Zool. v. 1904, p. 160. 
