212 



FIELD COLUMBIAN MUSEUM ZOOLOGY, VOL. V. 



steep, snout pointed; jaws equal; lips thick, the lower with a distinct 

 frenum; mouth rather small, maxillary 3^ in head; mandible 2$ ; 

 snout 2%; preorbital 4 in head; postorbital 2^ in head; interorbital 

 convex 3^ in head; diameter of eye 4 in head; eighth dorsal spine 



FlG. 68. ClCHLASOMA BARTONI Bean. 



2^ in head, last dorsal spine 2^ in head; middle rays of dorsal fin 

 not produced, their tips reaching slightly beyond base of caudal fin; 

 pectoral fin i % in head ; ventral rays not produced ; length of ventral 

 1^3 in head, tips not reaching first anal spine; caudal fin rounded; 

 least depth of caudal peduncle 2^; its length i>6 in its depth. 



Color dark brownish, sides with about 6 dark indistinct vertical 

 bars; no lateral band, or a very faint one; a dark caudal spot, sides of 

 head usually with small dark dots, these sometimes forming reticula- 

 tions on sides of head and above it ; very few or no dark dots on soft 

 dorsal, anal, or caudal fins. Length about 8 to 10 inches. 



This species is more robust and has a less pointed snout than 

 Cichlasoma steindachneri, which it most resembles. It has coarse, 

 blunt pharyngeal teeth. A number of specimens examined by me 

 were taken in the Rio Verde at Rio Verde by Dr. W. L. Tower of the 

 University of Chicago. 



200. Cichlasoma istlanum (Jordan & Snyder). 



Heros istlanus Jordan & Snyder, Bull. U. S. Fish Comm. 1900, 144, 

 fig. 21 ; Rio Ixtla, at Puente de Ixtla: Jordan & Evermann, 

 Bull. 47, U. S. Nat. Mus., 1900, 3174: Meek, Field Col. Mus. 

 Pub. 65, 1902, 120; Rio Ixtla; Puente de Ixtla, Morelos; Rio 

 Balsas. Balsas Guerrero. 



Basin of the Rio Balsas. (Yautepec; Jojutla; Chietla; Papayo, 

 Guerrero, collected by E. W. Nelson.) 



