BELONE.—CYPRINODONTIDA. 75 
Snout twice as long as rest of head. Diameter of eye 2} in length of postorbital part of head. Dorsal 15. 
Anal 17. Caudal peduncle somewhat depressed, the lateral line forming a slight keel. Silvery, back 
greenish; a bluish-silvery lateral stripe. 
Total length 1000 mm. 
Hab. Atlantic Coast from Cape Cod to Southern Mexico, entering rivers. 
2. Belone scapularis, Jord. & Gilb., 1881. 
Tylosurus scapularis, Jord. & Everm. Bull. U.S. Nat. Mus. xlvu. 1896, p. 711 ; Gilb. & Starks, 
Mem. Calif. Ac. Sci. iv. 1904, p. 51. 
Snout twice as long as restof head. Diameter of eye 33 to 4in length of postorbital part of head. Dorsal 14. 
Anal 15. Caudal peduncle not depressed. Silvery, back greenish ; a bluish-silvery lateral stripe; a dark 
blotch above the pectoral. 
Total length 450 mm. 
Hab. Pacific Coast of Panama, entering rivers. 
Fam. 2, CYPRINODONTIDZ. 
Head and body covered with cycloid scales *; no lateral line. Head depressed or moderately compressed, 
usually flat above; body more or less elongate, compressed posteriorly. Mouth protractile, bordered 
above by the premaxillaries only ; jaws with teeth; palate toothless? A single dorsal fin; pectoral 
fins placed low or moderately high; ventrals abdominal, of 5 to 7 rays; caudal usually rounded or 
truncate. 
This family comprises over two hundred species which may be referred to about 
twenty-five genera, from the fresh waters of America, Africa, and Southern and Eastern 
Eurasia. Most of the species are American, several of them entering the sea. Some 
species attain a length of 200 mm., but the majority do not grow to more than half 
that length. 
Synopsis of the Mexican and Central-American Genera. 
I. Oviparous. Males with the anal fin unmodified. Rami of the lower jaw firmly united. 
(CYPRINODONTINZ.) 
A. Teeth conical. 
1. Eyes with free margins. 
Teeth in bands, with an outer series of more or less strongly 
enlarged teeth. . . 2 ee ew he heheh )6hUdL FoNpuus. 
Teeth inasingle series . . . . . . ee ee ee OR «Lanta, 
2. Margins of eyes not free ; teeth in bands, with an outer series of 
enlarged teeth . eo ew e ew ss. . 8 Rivervs. 
B. Teeth tricuspid, in a single series oe 6 © « ee) 64 CYPRINODON. 
* The edges of the scales bear a series of prickles in the males of some species of Cyprinodon. 
+ Vomerine teeth are present in some Asiatic and African species. 
L 2 
