CATOSTOMUS DISCOBOLUS. 



179 



tion also is peculiar, and the form of the mouth is unlike that of any 

 other species. These features are all well shown in Girard's figure of 

 the species in the Ichthyology^ of the Mexican Boundary. 



The distribution of the species has not been well made out. I have 

 seen but one specimen, an adult male from the Gila region, apparently 

 the one from which Girard's figure was made. 



The type of Catostomus guzinaniensis cannot be found. The figure -xvas 

 made from a young fish, and the distinctions between it and laiipimiis 

 are such as often distinguish a young fish from an old one. It is better, 

 therefore, to unite the two than to admit an insufficiently characterized 

 nominal species. 



Specimens in United States National Artiscicm. 



37. CATOSTOMUS DISCOBOLUS Cope. 



Large-lipped Sucker. 



1672 — Catostomus discohol lis Cope, Ilayden's Geol. Surv. Wyo. 1870, 435. • 



Catostomus discobolus Cope & Yarrow, Wheeler's Expl. W. 100th Mer. v, Zool. 



677, 1876. 

 Catostomus discoholus Jordan & Copeland, Check List, 15G, 1876. 



ITacitat. — Idaho to Arizona. 



This interesting species is a Pantosteus in all but the technical char- 

 acter of the open fontanelle, and in this respect it is really intermediate, 

 as the fontanelle, in the adult at least, is reduced to a narrow slit. The 

 characters given in the analysis were taken from the Snake River spe- 

 cimen, 20,475, larger and in better condition than most or all of those 

 examined by Professor Cope. Professor Cope's original types came from 

 Green Eiver in Wyoming. 



