158 FIELD COLUMBIAN MUSEUM ZOOLOGY, VOL. V. 



of the fin in advance of origin of anal ; pectoral fin i % in head ; ventrals 

 (6) i to (?) i^a in head; modified anal fin of male with a hook 

 near its tip, the length of the fin i> in head; caudal appendage 

 pointed, i% to 2 in body; caudal peduncle deep, much compressed, 

 least depth i in head. 



Color light brown, lighter below; the lower half of the body in 

 life a bright yellow, which extends to the tip of the caudal filament. 

 The caudal filament is bordered above and below with black; a dark 

 lateral band from snout to upper third of caudal fin forming the black 

 on the upper part of the caudal filament; some specimens with from 

 2 to 4 vertical bars on the side near the tip of the pectoral fin ; dorsal 

 fin in both sexes much spotted with black. Length about 5 inches. 



Some of these fishes have large black blotches on sides and on 

 fins, which appear like large ink stains. This peculiar blotching 

 forms the basis of the description of the nominal species of Xipho- 

 phorus guntheri Jordan & Evermann. 



Eggs of females taken the last week of April have the eye spots 

 and the outline of the body formed. 



150. Xiphophorus montezumae Jordan & Snyder. 



Xiphophorus montezumce Jordan & Snyder, Bull. U. S. Fish Comm., 

 1900, 131, fig. ii ; Rio Verde, near Rascon, San Luis Potosi: 

 Jordan & Evermann, Bull. 47, U. S. Nat. Mus., 1900, 3156. 

 Basin of the Rio Panuco. (Rascon.) 



X 



FlG. 50. XIPHOPHORUS MONTEZUM/E Jordan & Snyder. 

 No. 6145, Leland Stanford Jr. University. 



Head 4 to 4^ ; depth 3 to 3,^ ; D. 1 1 to 13 ; A. 7 ; scales 9-27 to 29. 

 Body robust, deep, compressed, dorsal region somewhat elevated; 

 head broad; interorbital space slightly convex, 2 in head; snout $%', 

 eye 3 ; origin of dorsal midway between tip of snout and base of caudal ; 

 pectoral (3) equaling length of head to (?) i% in its length; origin of 

 anal fin under middle of dorsal; caudal appendage pointed, its length 

 almost equal to length of body. 



