126 Zoology of Colorado 



found low down in the Eocene near Walden, Colorado, so it 

 appears that the family has existed for many millions of years 

 in this region. Nevertheless, we apparently have today only 

 one really native species, the Green Sunfish (Apomotis cyanellus 

 of Rafinesque). It inhabits the region east of the mountains, 

 and also the Rio Grande. It is a greenish fish, darker above, 

 tinged with orange below, the opercular region, behind the head, 

 marked with blue; length about seven inches, or less. The re- 

 lated Blue Gill (Helioperca incisor), marked with double vertical 

 bars, has been introduced in ponds at Pueblo and in the Rio 

 Grande at Alamosa. The Rock Bass (Ambloplites rupestris), the 

 Calico Bass (Pomoxis sparoides), the Warmouth Bass (Chaeno- 

 bryttus gulosus), the Large-mouthed Black Bass (Aplites salmoides) 

 and the Small-mouthed Black Bass (Micropterus dolomieu) have 

 all been introduced in the interests of fishermen. Aplites ap- 

 proaches the Percidae in the form of its dorsal fin, the spinous and 

 soft portions being connected by a low isthmus. A. salmoides has 

 a lateral stripe or series of blotches along the lateral line; there 

 is no such stripe in M. dolomieu. The Calico Bass is profusely 

 mottled with dark green blotches, while the fins are striped and 

 spotted. The anal fin is very large. The Rock Bass is a yellow- 

 ish green fish with a red eye; the sides have numerous narrow 

 longitudinal dark stripes, interrupted at frequent intervals. The 

 anal fin has six spines. The Warmouth Bass, reaching a length 

 of six to ten inches, has a dark spot on the operculum, and the 

 sides of the head are longitudinally barred, the marking not 

 sharply defined. There are only three anal spines. 



