GEOLOGICAL SURVEY OF THE TERRITORIES. 43 O 



CATOSTOMUS DISCOBOLUS, (COPE ;) Sp. 110V. 



Eeinarkable for its very large lips, especially the upper. In general 

 it is allied to the C. griseum, being of the same cylindric form. The 

 upper lip is pendent, and somewhat expanded all round. Its margin 

 extends outside of that of the lower lip, where it joins it, thus forming 

 an entering right angle with it. The commissural margins of both are 

 wide and abruptly separated from the tuberculated portions. Tubercles 

 subequal; those of the lower jaw projecting in a convex enlargement, 

 concentric with the lower commisure; behind deeply incised. Muzzle 

 projecting a little beyond upper lip; head wide, flat above; eye superior, 

 small, entering length of head 5.5 times; three times in muzzle. 

 Phryngeal bones expanded below ; teeth delicate laminar, with acute 

 inner cusp. Length of head, entering total to end of caudal scales, 

 four and a half times ; ventral fins originating opposite posterior third 

 of dorsal, barely reaching vent ; pectorals well separated ; isthmus very 

 wide. Badii, I). 11; A. 8; V. 9. Scales in 38-40, longitudinal series 

 between dorsal and ventral tins ; color, olive brown above, black on 

 head, passing into light yellow below, gradually on the body, abruptly 

 on the head. 



M. 



Total length 0.153 



Length to orbit 016 



Length to opercular border 029 



Length to dorsal fin 065 



Length to ventral fin 0695 



Length to anal .097 



Width of frontal bones 011 



Length of ventral fins 02° 



j*j-j 



Two specimens, one certainly, the other probably, from the Green Biver, 

 Wyoming. This striking species was discovered by Cam. Carrington. 



This species may be compared with the C. plebeius, Girard, and C. 

 generosus, Girard. In the first the eye is larger and more median, the 

 scales are subequal, and there are only eight ventral rays. In the second 

 the eye is also larger. In neither is the great development of the lip 

 seen. 



MINOMTJS DELPHINUS, (COPE,) Sp. nov. 



The subequal size of the scales of this species would refer it indif- 

 ferently to the true group Catostomus of Girard, or his group Minomus, 

 which he did not distinguish clearly. The preceding species would 

 enter his Acomus, which is, however, only an undefined group of species, 

 to which, by the way, the type of Catostomus, C. teres belongs. 



This species is especially distinguished from those heretofore de- 

 scribed by the shortening of the caudal part of the vertebral column, 

 and the consequent posterior position of the dorsal fin. Add to this a 

 short, wide head, ancf thick body, and its physiognomy is expressed. 



The dorsal outline is arched, the head flat above, but elevated behind, 

 and much depressed on the muzzle. The muzzle is wide and does not 

 project beyond the upper lip, which is appressed to its lower face and 

 bears four rows of warts ; its smooth commissural part is narrow. On 

 the lower lip the tubercles advance nearly to the commisure ; this lip 

 is deeply emarginate posteriorly ; the eye enters the length of the head 

 five times, two and one-half times measuring the muzzle, and twice the 

 interorbital region. Head four and two-thirds times in length to end 

 of caudal basal scales. 



