PLECTOSPONDYLI CYPRINIDAE APOCOPE HENSHAVII. 645 



Apocope; but the specimens originally described under this name from 

 Logan, Utah, are not fully grown. I suspect that in adults of this genus 

 the lateral line will be found to be developed. The genus will then require 

 to be further defined in expression of its distinctive features as compared 

 with Ceraticlilhys. The character to be added is the position of the dorsal 

 fin, which is behind the line of the ventrals, as in Rhiniclithys, while in 

 Ceraticlithys the dorsal is on or before the line of the ventrals. The known 

 species of Apocope, Cope, are these : A. carringtonii, Cope ; A. henshavii, 

 Cope; A. vuherata, Cope; A. couesii, Yarrow ; A. ventricosa, Cope; and A. 

 oscula, Girard. 



The species of this genus are all of small size, and difficult of deter- 

 mination. For the purpose of aiding the student, the following synoptic 

 table is given : 

 A. The lateral line very short Apocope. 



Scales larger, |5 60 ; muzzle short ; D. I. 8 A. carringtonii. 



AA. The lateral line complete or imperfect on a part of the caudal peduncle, 



JEritrema. 



Scales medium, ^ 67 ; D. I. 9 A. JienshaviL 



Scales |5 70 ; lateral line imperfect ; muzzle short ; D. I. 8, A. vulnerata. 



Scales |5 63 ; lateral line sometimes imperfect ; muzzle long ; D. I. 8, 



A. oscula. 



Scales small, j-jj 80 ; muzzle long ; D. I. 8 .A. couesii. 



Scales very small, ^ 89-95 ; muzzle not elongate ; D. I. 8, A, ventricosa. 



APOCOPE CARRINGTONII, Cope. 



Apocope carringtonii, COPE ill Rep. U. S. Geol. Surv. Montana, &c., 1871, 472. 

 Warm Springs, Utah. 



APOCOPE HENSHAVII, Cope. 

 PLATE XXVIII, FIGS. 2, 2a. 



Rhiniclithys henshavii, COPE, Proc. Aui. Phil. Soc. Phila., 1874, 133. Id., Plagop. & 

 Ichthy. Utah, 1874, 7. 



An elongate species, with small scales and overhanging but obtuse 

 muzzle, resembling a Ceratichthys of the group of C. nubilus (Rhinichtliys), 



