176 FIELD COLUMBIAN MUSEUM ZOOLOGY, VOL. V. 



This is one of the largest species in the genus. It is very abundant 

 in the lakes near the City of Mexico, and in this region is the most im- 

 portant food fish. By far the larger number of white fishes (Pescadas 

 blancas) offered for sale in the markets of the City of Mexico belong 

 to this species. 



163. Chirostoma c ha pa hi- Jordan & Snyder. 



Chirostoma chapalce Jordan & Snyder, Bull. U. S. Fish Comm. 



1900, 135, fig. 13; Lago de Chapala, Ocotlan, Jalisco: Jordan 



& Evermann, Bull. 47, U. S. Nat. Mus., 1900, 3159: Pellegrin, 



Bull. Mus. Hist. Nat. Paris, 1901, 205; Estado de Jalisco: 



Meek, Field Col. Mus. Pub. 65, 1902, 115; Ocotlan; La Palma. 



Basin of the Rio Lerma. 



FIG. 58. CHIROSTOMA CHAPAL/E Jordan & Snyder. 



No. 6155, Leland Stanford Jr. University. 



Head 4; depth 5^! D. iv-io; A. 21; scales 13-49. Body slender, 

 compressed, its deepest part below first dorsal; snout pointed, its 

 length 3 ; mouth oblique, the lower jaw slightly the longer; maxillary 

 not quite reaching vertical from anterior margin of the orbit; teeth 

 minute, in bands, not arranged in definite rows; no teeth on vomer or 

 palatines; diameter of eye 3$ in head; origin of spinous dorsal mid- 

 way between base of caudal and nostril ; pectoral i % in head ; ventrals 

 2^; base of anal fins equals the length of the head; lateral line on 

 eighth row of scales, not well defined; scales with crenate edges, the 

 scales on nape and before pectorals reduced in size; the others quite 

 uniform; gill rakers long and slender, 30 on first gill arch; vertebrae 

 24+20 = 44. 



Color silvery, translucent; a dark lateral band; scales on dorsal 

 region edged with dark dots. Length about 4 inches. 



Very abundant in Lago de Chapala and neighboring region. 



164. Chirostoma grandocule Steindachner. 



Chirostoma grandocule Steindachner, Anzeiger der Kais. Akad. d. 

 Wiss. Wien, 1894, 149; Lago de Patzcuaro, Michoacan: Jordan 

 & Evermann, Bull. 47, U. S. Nat. Mus., 1898, 2839: Meek, 

 Field Col. Mus. Pub. 65, 1902, 115; Ocotlan; La Palma; Patz- 

 cuaro. 



