MAY, 1902. THK ICHTHYOLOGY OF MEXICO MEEK. 81 



Colonia Juarez and San Andres are rather darker than those from 

 Minaca. 



Lago de Castillos at Bustillos was dry, but a few specimens 

 were taken from two small ponds near by. Although but a few 

 feet apart the fishes from one were very dark while the others 

 were much lighter than any taken elsewhere. 



Lago de Patos at San Jose was nearly dry. Fishes were 

 reported to be in a few holes in the bed of the lake, but a reason- 

 able amount of seining did not procure any specimens. None 

 were taken from a large ditch at Ahumada, some ten miles above 

 .the lake. 



Mr. Jackson, an American at Ahumada, informed me that 

 there were suckers and two species of other fishes, similar to 

 fishes found in the Gila River, in the River Carmen, some 

 twenty miles above Ahumada. One had the caudal peduncle 

 much more slender than in the other; one was probably this spe- 

 cies, the other a Gila, probably the same species found in the 

 Rio Paphigochic, a tributary of the Rio Yaqui at Minaca. 



Specimens of this species are in our collection as follows-' 

 Colonia Juarez; Santa Maria; Chihuahua: Bustillos: San Andres; 

 Minaca. At all these places it was very abundant. It reaches a 

 length of about 12 inches. 



This species is distributed throughout the larger part of the 

 Rio Grande and adjoining river basins. None were taken at 

 Jimenez and Santa Rosalia. 



Aztecula Jordan & Evermann. 



The three species of this group have a very robust body and 

 much smaller scales than the species of Notrofiis, to which they 

 seem to be more nearly related. 



Aztecula mexicana,*sp. nov. 



Type, No. 3606, F. C. M. Length, 2$ inches. 



Locality, Rio Moctezuma, San Juan del Rio, Queretaro, 

 Mexico. 



Head 4; depth 4^; D. 8; A. 7; scales 9-59-7. Body robust, 

 back slightly elevated, its highest point over pectoral fin 

 and some distance in advance of the dorsal: snout blunt; 

 mouth terminal, oblique, lower jaw the shorter; eye small, 

 its diameter 4^ in the head; iris silvery: snout 4 in head: interor- 

 bital area 3 in head. Origin of dorsal fin midway between base 

 of caudal and the eye, 31 scales in a series before dorsal fin; 



