Fam. V. Cyprinid^e. Fam. VI. Characinid^;. 83 



convex; snout rather long, slightly pointed; its length 3! in head; 

 mouth low, terminal, oblique; the jaws subequal, the maxillary- 

 opposite posterior nostril; barbel evident in young, inconspicuous 

 in the adult, its position not quite terminal; interorbital space broad, 

 flattish; eye 37-3 in head; preorbital broad; origin of dorsal inserted 

 over or a little behind ventrals, the latter reaching to vent. 



Color olivaceous, dusky above; sides silvery; a narrow plumbeous 

 lateral band ending in a small caudal spot in young individuals; fins 

 all plain. Length about 4 inches. 



This species is known only from the type locality. 



Subfamily Plag-opterinae. 

 34. Plagopterus Cope. 



Plagopterus Cope, Proc. Amer. Phil. Soc. Phila., 1874, 301. (Type, 

 Plagopterus argentissimus Cope.) 



Body slender; mouth terminal; a barbel at the extremity of the 

 maxillary; teeth 2, 5-4, 2, hooked, without grinding surface; body 

 without scales; dorsal fin short, posterior, with a strong spine 

 composed of 2 spines, the posterior one being received into a longi- 

 tudinal groove of the anterior; inner border of ventral fins adherent 

 to the body. 



79. Plagopterus argentissimus Cope. 



Plagopterus argentissimus Cope, Proc. Amer. Phil. Soc. Phila., 

 1874, 130; San Luis Valley, Colorado: Jordan & Evermann, 

 Bull. 47, U. S. Nat. Mus., 1896, 329: Gilbert & Scofield, Proc. 

 U. S. Nat. Mus., 1898, 496; mouth of Rio Gila at Yuma. 

 Colorado River Basin in Colorado to Ft. Yuma, Arizona. 

 Head 4; depth 6; D. 11, 7; A. 10. Body slender; head rather 

 broad, the muzzle slightly depressed, overhanging the rather small, 

 horizontal mouth; lips thin; maxillary reaching front of eye; eye 

 moderate, 4^ in head; dorsal fin entirely behind ventrals, the first 

 spine curved, longer than the second; soft rays of dorsal thickened, 

 ossified at base; lateral line complete, slightly deflexed. 



Color silvery; back dusky, with minute black dots. Length about 

 2% inches. A singular little fish. 



Family VI. Cliaraciniche. 



The Characins. 



Body usually rather elongate, compressed and covered with cycloid 

 scales; head naked; margin of the upper jaw formed mesially by 

 the premaxillaries and laterally by the maxillaries ; no barbels ; pre- 



