216 Bulletin 4/, United States National Museum. 



347. HYBOGNATHUS MELAXOPS (Giranl). 



Head 4 to 4i ; depth 3i to 3J. D. 8 ; A. 7 ; scales 7-36 to 38-i ; teeth 4-4. 

 Body deeper than iu related species ; snout rouuded; eye medium. Black- 

 ish above, sides smoky, with black dots ; a black spot at base of caudal. 

 Leu<j;th 2^ inches. Streams of Coahuila, Chihtiahua, and Nuevo Leon. 

 Two specimens collected by Mr. Woolmau in Chihuahua Kiver af^ree with 

 H. episcopa in all respects except that the depth is 3f and the scales 42 or 

 43. It is doubtful whether the two species are really distinct. {n'tXa^, 

 black; <"))/;, eye.) 



Dicmda melanops, Girard, Proc. Ac. Nat. Sci. Pliila., 185G, 178, Buena Vista, Coahuila. 



(Type, No. 41. Coll. Couch.) 

 /)ioii(?((m»(7,/,(iiRARD, Proc. Ac. Nat. Sci. Phila., 1856, 178, Guajuco, Monterey, and Cadereita, 



New Leon. (Type, No. 103, (20227). Coll. Miillhausen.) 

 JIijlxjijnathuK iiidanopsi, Jordan, Bull. U. S. Geol. Surv., iv. No. 2, 402, 1878. 



348. HYBOGNATHUS PLUMBEA* (Girard). 



Head 4|^; depth 4 J. D. 8; A. 7 ; lateral line 53 to 58. Body rather slen- 

 der. Head moderate, rounded iu front. Lower jaw included. Dorsal 

 inserted before ventrals. Color uniform, sometimes a black spot at the 

 base of the caudal. Tributaries of Arkansas River in Indian Territory. 

 (Grirard.) (plumheus, lead-colored.) 



Dionda phimhra, Girard, Proc. Ac. Nat. Sci. Phila., 1850, 178, Canadian River. (Coll. 



Mollhausen. 

 Dionda spadicea, Girard, Proc. Ac. Nat. Sci. Phila., 1856, 178, Fort Smith, Arkansas. (Coll. 



Mollhausen.) 

 Dionda f/risfa, Girard, Pacific K. K. Surv., x, 230, pi. Lii, figs. 6-10, 1858, 20 miles west of 



Choctaw Agency. (Coll. Mollhausen.) 

 Zophendnm phnnbeum, Jordan & Gilbert, Synopsis, 155, 1883. 



I loS. PIMEPHALES, Rafiuesque. 



(Fat-heads.) 



Pimephalen, Eafinesque, Ichth. Oh., 52, 1820, {promelas). 



Hyhorhynckus, Aoassiz, Aiiier. Journ. Sci. Arts, 1855, 22, {nolalun). 



CoUsciix, Cope, Haydeu's Kept. Gcol. Surv. of Wyoming, 1872,437, {parietalix = young of promelas). 



Body rather robust, little compressed. Head short and rounded. Mouth 

 small, inferior ; upper jaw protractile ; no barbel. Teeth 4-4, with oblique 

 grinding surface, usually but one of the teeth hooked. Dorsal over ven- 

 trals, its first (rudimentary) ray separated from the rest by membrane, 

 not adnate to it, as usual in minnows ; this character is most distinct in 

 adult males, in which the skin of the first ray is thickened. Anal basis 

 short. Intestinal canal elongate. Peritoneum black. Pseudobranchise 

 present. Scales rather small. Lateral line complete or variously incom- 

 plete. Size small. Breeding males with much black jiigment and with 

 large warts on the head. {in/iEh'/c, fat; ke^cM/, head.) 



a. Lateral lino more or less incomplete ; body very short and stout. promelas, 349. 



aa. Lateral line complete ; body moderately elongate. notatus, 350. 



*The nominal species hero united as Hyhoijnathis plumbea are all unknown to us. Girard 

 figures all of them as having small scales, some 53 to 58 in the lateral line. In general appear- 

 ance these figures seem to agree, and except for the scales, they seem to be close to the other 

 species called Dionda. It ia possible that their relations are with Algamea rather than Dionda. 

 It may also bo that the scales are erroneously figured by Girard. 



