CTPRINODONT FISHES. 985 



Zygonecies hrachypterus Cope, Bull. U.S. N"at. Mvis. xx. 1880, 

 p. M. 



Zi/gonectes inurics Jord. & Gilb. Pi-oc. U.S. Nat. Mus. 1882, 

 p. 543. 



$ . Depth of body 3| to 4^; in the length, length of head 

 3-1- to 4^. Diameter of eye 3| to 4 in length of head, interorbital 

 width \^ to 2. 30 or 31 scales in a longitudinal series. Dorsal 

 6-7 ; origin above posterior part or end of anal, equidistant from 

 some part of operculum or base of pectoral and base of caudal ; 

 longest rays -^ to ^ length of head. Anal 10-11. Pectoral from 

 ^ to nea.rly as long as head ; pelvics reaching vent or origin of 

 anal. Brownish or olivaceous above, yellowish or silvery below ; 

 scales dark- edged ; usually a dark suborbital bar ; dorsal and 

 caudal fins with small dark spots. 



Florida to Tampico ; Mississippi. 



Numerous females, measui-ing up to 50 mm. in total length, 

 from Florida and Louisiana ; one from Tampico. 



4. Gambusia SENILIS. (Text-fig. 168 E.) 



? Heteraudria nohiiis Baird & Girard, Proc. Acad. Philad. 1853, 

 p. 390. 



? Gamhusia nohiiis Girard, U.S. Mex. Bound. Surv., Fish. p. 71, 

 pi. xxxix. figs. 8-11 (1859). 



Gambusia senilis Girard, Pi-oc. Acad. Philad. 1859, p. 122. 



5 . Depth of body 3 to 3^ in the length, length of head 3i to 4. 

 Diameter of eye 3^- in length of head, interorbital width 2. 

 30 scales in a longitudinal series. Dorsal 8-9 ; origin above 

 middle or posterior part of anal, equidistant from base of pectoral 

 and base of caudal; longest rays |^ length of head. Anal 9-10. 

 Pectoral |- length of head ; pelvics reaching vent. Least depth 

 of caudal peduncle |^ length of head. Brownish above, yellowish 

 below ; scales dark-edged, especially on sides of abdomen ; a dark 

 suborbital bar and a dusky lateral band from eye to base of 

 caudal. 



(S . Origin of dorsal fin equidistant from prseoperculum and 

 base of caudal. 



Chihuahua, Mexico. 



Several females, 45 to 50 mm. in total length, and one 

 male of 25 mm. 



5. Gambusia NicARAGUENSis. (Text-fig. 168 A.) 



Gamhusia nicaraguensis Giinth. Cat. Fish, vi. p. 336 (1866), and 

 Trans. Zool. Soc. vi. 1868, p. 483, pi. Ixxxii. fig. 3 ; Regan, Biol. 

 Centr.-Amer., Pisces, p. 96 (1907). 



Faragamhusia nicayaguensis Meek, Publ. Columbian Mus , Zool. 

 v. 1904, p. 133. 



2 . Depth of body about 3 in the length, length of head 

 3^ to 4. Diameter of eye 3 to 3.V in length of head, inter- 

 orbital width 2, 28 scales in a longitudinal series. Dorsal 7-8 ; 



