86 FIELD COLUMBIAN MUSEUM ZOOLOGY, VOL. III. 



lateral line complete, decurved above pectorals; first dorsal ray 

 reaching beyond tip of the last ray when the fin is deflexed. 



Color, dark olive, white below, the line between the colors 

 distinct and extending from below eye to one-quarter distance from 

 ventral surface of caudal peduncle. A dark vertebral and a dark 

 lateral band. This species differs from Evarra -eigenmanni in 

 having smaller scales, a higher and longer anal fin, a more pos- 

 terior dorsal fin and a more slender body. Tlahuac, Lake 

 Chalco. 



Evarra eigenmanni Woolman. 



A few small specimens of this species were taken in Lake 

 Chalco at Tlahuac. 



Hybopsis altus (Jordan). 



This species is usually found in clear running water. It 

 reaches a length of about 5 inches. Aguas Calientes: Lagos: 

 Celaya; Acambaro. 



Rhinichthys simus Garman. 



Head 3-; depth 5$: D. g; A. 8: scales 60: snout 22 in the 

 length of the head: eye small, 5 in head: origin of dorsal fin mid- 

 way between base of caudal and anterior nostril; lateral line 

 straight, complete: snout long, somewhat depressed, mouth 

 inferior. 



Color light olivaceous, a dark lateral band, no silvery one; 

 a small dark caudal spot. Longest specimen 2.32 inches. 

 A few specimens taken at Santa Rosalia. 



CHARAC1N1D/E. 

 Tetragonopterus argentatus ( Baird & Girard). 



Anal rays 19 to 21. This species is very abundant in the 

 head waters of the Rio Conchos. Largest specimens nearly 4 

 inches in length. Ovaries not developed enough to give one any 

 definite idea of the spawning time. 



Chihuahua: Santa Rosalia: Jimenez. 



Tetragonopterus mexicanus Filippi. 



This species was first noticed by Filippi in 1853, and is 

 reported by him from the City of Mexico. This species, or 

 rather this genus, does not occur in the lakes about the City of 



