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, Scombresocidre and Cyprinodontidte, which may be distinguished from 

 other soft-rayed fishes with abdominal ventral fins by the following combination ot 

 characters : — " Jaws toothed ; prgemaxillaries 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 



bodv 1. SCOMBRESOCID.'E. 



No lateral line 2. Cypkinodontid.s. 



Fam. 1. SCOMBRESOCID^. 



The Scombresocida3 are marine Fishes of the tropical and temperate seas. Some of 

 the species of Belone and Hemlrhamplms enter rivers, and a few permanently fluviatile 

 forms are now usually referred to distinct genera. 



1. BELONE, Cuv., 1817. 



Belone, Giinth. Cat. FisJi. vi. p. 234 (18GG). 



Tylosurus (Cocco), Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1896, p. 708. 



]jody slender, elongate. ]\[outh with wide Literal cleft, hoth jaws beiug 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 asj'm metrical, placed high ; ventrals 0-raj'ed, inserted posteriori}'. 



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, .lord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1896, p. 714 ; Meek, Publ. Columbian 

 Mus., Zool. V. 1904, p. IGO. 



