CYPEINODON, 83 



Only two well-established species, C. macularius and C. bovinus, have been recorded 

 from Mexico, but two others known to occur in the Eio Grande system are probably 

 to be met with in its southern tributaries and are therefore included here. In all 

 these the origin of the dorsal fin is about in the middle of the length of the fish 

 (without the caudal fin), and the anal commences below the posterior part of the dorsal. 



Synopsis of the Mexican and Central-American Species*-. 



I. Longest dorsal rays^ in the male^ only a little more than ^ the length of head, 



less than the length of base of the fin . 1. elejans. 



II. Longest dorsal rays, in the male, from § to as long as the head, not shorter than the base of 

 the fin. 



A. Longest anal rays considerably shorter than those of the dorsal. 

 Diameter of eye 3^ to 4 in the length of head (in specimens measuring up 



to 60 mm.) ; pectoral | the length of head 2. bovinus. 



Diameter of eye 3 to 3^ in the length of head (in specimens measuring up 



to 70 mm.) ; pectoral as long or nearly as long as the head 3. variegatus. 



B. Longest anal rays scarcely shorter than those of the dorsal 4. macularius. 



1. Cyprinodon elegans. 



Cyprinodon eleyans, Baird & Girard, Proc. Ac. Philad. 1853, p. 389'; Girard, U.S. IMex. Bound. 

 Surv., Fish. p. 66, t. 37. figs. 1-7 (1859)=; Jord. & Everin. Bull. U.S. Nat. Mus. xlvii. 

 1896, p. 675 \ 



Depth of body i'| in the length, length of head 3j. Snout aa long as e}-e, the diameter of Avhich is 3i in 

 the length of head; interorbitul width 2^ in the lengtli of head. 1'6 scales in. a longitudinal series. 

 Dorsal 11 ; longest ra5-s less than the length of base of the fin, scarcely more than ^ the length of head, 

 shorter than the longest anal rays. Anal 11. Pectoral ^ the length of head. Caudal subtruncate. 

 Least depth of caudal peduncle 1| in its length, -| the length of head. Dark brownish above, yellowish 

 beneath ; upper parts with irregular dark spots ; a dark band along the middle of the side ; fins pale ; 

 basal half of dorsal with small dark spots ; caudal with a narrow blackish posterior edge. 



llab. Caiuanche Springs, Rio Grande ^ ". 



Here described from a single specimen, a male, measuring 50 mm. in total length, 

 received from the Smithsonian Institution. 



2. Cyprinodon bovinus. 



Cyprinodon hoviaus, Baird & Girard, Proc. Ac. Philad. 1853, p. 389 ' ; Girard, U.S. & Mex. Bound. 

 Surv., Fish. p. 67, t. 37. figs. 12-18 (1859)=; Jord. & Everm. Bulb U.S. Nat. Mus. xlvii. 

 1896, p. 673'. 



* C. carpio, Giinth., from Florida, apparently does not extend further south. It is recognizable by the 

 largo eye (diameter \ the length of head in specimens of 80 mm.) and by the humeral scale, which is not 

 enlarged. 



C. martcc, Steiud., from the coast of Colombia, may occur in Central America ; it appears to have a more 

 slender body than the species described here. 



M 2 



