BELOAE.— CTPEINODONTID^. 75 



Snout twice as long as rest of head. Diameter of ej-e 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, 



llah. Atlantic Coast from Cape Cod to Southern Mexico, entering rivers. 



2. Belone scapularis, Jord. & Giib., 1881. 



Tylosurus scapularis, Jord. & Everni. EuU. U.S. Nat. Mus. xlvii. 1896, p. 711 ; Gilb. & Starks, 

 Mem. Calif. Ac. Sci. iv. 1904, p. 51. 



iSnout twice as long as rest of head. Diameter of eye 3i to 4 in 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. 



llah. Pacific Coast of Panama, enterini^ rivers. 



ram. 2. CYPRINODONTID^. 



Head and body covered witli 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 proamaxillaries only ; jaws with teeth ; palate toothless t. A single dorsal fin ; pectoral 

 fins placed low or moderately high ; ventrals abdominal, of 5 to 7 rays ; caudal usually rounded or 

 truncate. 



Tliis 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 aoal fin unmodified. Rami of the lower jaw firmly united. 

 (Cyprinodontin^.) 



A. Teeth conical. 



1. Eyes with free margins. 



Teeth in bands, with an outer series of more or less strongly 



enlarged teeth 1. Fundulus. 



Teeth in a single series 2. Lijcania. 



2. Margins of eyes not free ; teeth in bands, with an outer series of 



enlarged teeth 3. Rivultis. 



B. Teeth tricuspid, in a single series 4. Cyprinodon. 



* The edges of the scales bear a series of prickles in the males of some species of C ijprinodou. 

 t Vomerine teeth are present in some Asiatic and African species. 



L 2 



