PANTOSTEUS PLEBEIUS. 185 



scales, and form of body, Pantosteus plebeius seems to resemble Catosto- 

 mus insignis and C. clarJcii, and to diverge from the type of discobolus, 

 gcnerosuSj and platyrliynclius.* 



* Professor Cope (in lit.) dissents from the identification above made, maintaining 

 that P. dcJjjhinus and P. bardus are at least specifically distinct from each other, what- 

 ever may be the relation of either to P. pltbtius. As I have seen none of the three 

 forms in question, I let the above stand as I had written it, and quote the original de- 

 scriptions of the three nominal species: 



MINOMUS PLEBEIUS Grd. " Body sub-fusiform, compressed. Head elongate, subcon- 

 ical, forming the fifth of the entire length. Mouth of medium size. Eyes large, sub- 

 elliptical, their longitudinal diameter being contained about live times in the length of 

 side of head. Dorsal fin subquadrangular, its anterior margin being equidistant be- 

 tween the tip of the snout and the first ludimentary rays of the upper lobe of the 

 caudal. The latter is slightly concave posteriorly, and the lobes rounded off. The 

 base of the anal is contained nearly three times in its height, and when brought back- 

 wards its tip extends to the rudimentary rays at the inferior lobe of the caudal fin. The 

 veutrals are inserted under the posterior third of the dorsal ; bent backwards, their tip 

 does not reach as far as the anus. The pectorals are of medium development, sub- 

 ovate, posteriorly acute. 



"The scales are of medium size, considerably largest on the peduncle of the tail. 

 Twenty-eight to thirty rows from the base of the ventrals to the dorsal fin. About 

 eighty in the lateral line, which is not discernible as far back as the base of the caudal 

 fin. 



" The color as preserved in alcohol, is dark brown on the upper regions, faintly mot- 

 tled with blackish patches. The sides and belly exhibit traces of orange in some of 

 the specimens, in others it is pale yellowish. The fins are unicolor; the dorsal, caudal, 

 and pectorals, blackish brown ; the anals and ventrals yellowish." (GiRAUD, Ich. U.S. 

 and Mcx. Boundary SUIT. , p. 38, figs. 1-4, plate xxii.) 



MIXOMUS DELPHINUS Cope. " The subequal size of the scales cf this species would 

 refer it indifferently 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 described 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, and 

 thick body, and its physiognomy is expressed. 



" The dorsal outline is arched, the head flat above, but elevated behind, and much de- 

 pressed 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 com- 

 nrissuial part is narrow. On the lower lip the tubercles advance nearly to the com- 

 missure ; 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 inter- 

 orbital region. Head four and two-thirds times in length to end of caudal basal scales. 

 Scales in thirty longitudinal series, between dorsal and ventral fins; ventrals remark- 



