656 ZOOLOGY FISHES. 



G 



S ; radii, D. I. 8 ; A. I. 7. Depth 4.6 in length without caudal fin ; length 



3 



of head four times in the same. Orbit one-third length of head, equal to 

 interorbital width. Side of muzzle, top of head, and scales above lateral 

 line dusted with black. 



GILA, Bd. & Gir. 



Professor Cope has long been satisfied that the species included in the 

 genera Gila, Bd. & Gir., and Clinostomits, Gir., by Girard, could not be 

 retained in distinct genera, and that the greater number of the Tigomcc 

 of the same author must be included in the same natural genus. Such a 

 genus will then include Cyprinida, with the external series of teeth 5-4 of 

 the raptorial type, and without grinding surface ; no barbels ; dorsal fin 

 behind the line of the ventrals, without strong or separated spine. The 

 typical Gil have a peculiar physiognomy, but the transition to the Clino- 

 stomus type is complete through G. nacrea, Cope, and G. (Clinostomus) 

 pandora, Cope. 



From the last to the large-scaled species, the transition is equally unin- 

 terrupted. The species of the genus then are the following : 



Gila plilegetlwntis, Cope (Clinostomus). 

 Gila affinis, Girard (Clinostomus). 

 Gila fundidoides, Girard (Clinostomus). 

 Gila margarita, Cope (Clinostonms). 

 Gila proriger, Cope (Clinostonms). 

 Gila tania, Cope (Clinostomus). 

 Gila montana, Cope (Clinostomus). 

 Gila liydroplilox, Cope (Clinostomus). 

 Gila ardesiaca, Cope. 

 Gila humboldtii, Girard (Tigonia). 

 Gila pandora, Cope (Clinostomus). 

 Gila gula, Cope. 



