32 FIELD COLUMBIAN MUSEUM ZOOLOGY, VOL. V. 



b. Scales in the lateral series 65; 30 scales in a PAGE 



series between nape and dorsal fin sonorensis 32 



bb. Scales in the lateral line 75; 31 scales in a 



series between nape and dorsal fin bernardini 32 



aa. Scales in the lateral line 80; about 45 scales in 



a series between nape and dorsal fin conchos 33 



26. Catostomus sonorensis Meek. 



Catostomus sonorensis Meek, Field Col. Mus. Pub. 65, 1902, 75; 

 Minaca. 



Upper tributaries of the Rio Yaqui. 



Head 4; depth 4%; D. 12; A. 7; scales 11-65-10. Body robust, 

 profile very convex; top of head flattish, broad; interorbital 2% in 

 head; lips thick, papillose, the papillae on upper lip in 8 or 9 rows; 

 lower lip very broad, from anterior to posterior margin 4^ in head; 

 the two halves meeting at a very obtuse angle; dorsal fin as high as 

 long, its base i| in head; origin of dorsal fin slightly nearer base of 

 caudal fin than tip of snout ; margin of dorsal fin slightly convex ; base 

 of ventrals under middle rays of dorsal fin; pectoral fin if in head; 

 distance from tip of pectoral to base of ventral i in pectoral fin; 

 ventrals if in head, their tips nearly reaching anal fin; lateral line 

 slightly decurved anteriorly; no fontanelle; caudal fin deeply emar- 

 ginate; lobes equal; scales on anterior half of body much reduced. 



Color steel blue to brownish, white below; young specimens have 

 the dark lateral blotches. Length about 12 inches. 



27. Catostomus bernardini Girard. 



Catostomus bernardini Girard, Proc. Acad. Nat. Sci. Phila., 1856, 

 175; San Bernardino Creek, tributary of Rio Huagui, west of 

 Sierra Madre Mts., Mexico: Girard, Mex. Bd. Sur., 40, xxin, figs. 

 1-5, 1858; San Bernardino Creek: Jordan & Evermann, Bull. 47, 

 U. S. Nat. Mus., 1896, 178: Rutter, Proc. Cal. Acad. Sci., 1896, 

 258; Rio Yaqui, Sonora: Bean, Bull. Amer. Mus. Nat. Hist., 

 1898, 166, Sonora. 

 Pacific slope streams in Sonora. 



Head \ l /t ; depth about 4^ I D. 1 2 ; A. 7 ; scales 75. Body elongate, 

 rather slender; head small; lips broad, the lower deeply incised; eye 

 large, 4 in head ; origin of the dorsal fin slightly nearer tip of snout than 

 base of caudal ; margin of dorsal fin subconvex ; base of dorsal a little 

 less than length of longest ray; pectorals about \\ in the head; scales 

 on anterior half of the body much reduced in size, 31 in a series be- 

 tween nape and first dorsal ray; fontanelle large. 



Color uniform, purplish black and yellowish white beneath. This 

 species probably reaches a length of 1 2 inches. 



