82 FIELD COLUMBIAN MUSEUM ZOOLOGY, VOL. III. 



caudal peduncle slender, its least depth 2\ in the head; pectorals 

 short, their tips reaching about half way to base of ventrals, 

 1 2 in head: ventrals nearly reaching vent, 2 in head. 



Lateral line decurved and wavy, complete or missing on a few 

 scales only. 



Color, dark olive above, lighter below: a faint lateral band 

 most conspicuous on last half of body; a faint caudal spot, which 

 is- more prominent in the young. 



This species differs from Aztecula azteca in the smaller scales, 

 and more slender peduncle and the larger eye. 



Eggs well developed, spawning season about June ist. 

 Abundant at San Juan* del Rio. Not taken elsewhere. 



Aztecula azteca (Woolman. ) 



A few specimens were taken from a small ditch by the side 

 of the Interoceanic Railroad, -near Texcoco Lake. These speci- 

 mens agree with the description given by Woolman. A few were 

 also taken in Lago de Chalco. 



At present three species of this group are known: one, Aztecula 

 azteca, from the Valley of Mexico; one, Aztecula mexicana, from 

 Rio Moctezuma, a tributary of the Rio Panuca; and one, Aztecula 

 lentil's, from Lake Lerma, near the head waters of the Lerma 

 river. Texcoco. 



Notropis robustus, sp. nov. 



Type. No. 3548, F. C. M. Length, 2.46 inches. 



Locality, Rio Conchos, Jimenez, Chihuahua, Mexico. 



Head 3^: depth 4; D. 9; A. 8; scales 6-37-4. Body robust, 

 back little arched, its highest point being just in front of dorsal 

 fin: snout blunt; mouth nearly terminal, slightly oblique, large; 

 maxillary 3^ in the head, its tip reaching vertical from pupil. 



Lateral line slightly decurved, complefe; eye large, its diam- 

 eter 3^ in the head: interorbital space 3 in head. 



Pectoral fins long, nearly reaching ventrals, \\ in head; ven- 

 trals 2 in head. Origin of dorsal midway between base of caudal 

 and nostril, 15 scales in a series before dorsal fin: caudal peduncle 

 slender, its least depth 2^ in head. 



Color olivaceous, a dark lateral band from snout to base of 

 caudal, which ends in a small spot at base of middle caudal rays; 

 chin white. 



This species resembles Notropis blennius, from which it 

 differs in having a larger head, a broader and more robust body, 



