174 Bulletin 47, United States National Museum. 



Decactyli'S, ((leKo, ten; fiaxTuAos, toe, i. c, ventral rays): 



hh. Scales .small, but larger than in the preceding group, the uumbor in the lateral line 

 5G to 75. 

 /. Scales in lateral lino 70 to ".'>; lower lip broaJ. 

 ij. Dorsal fin moderate, of 11 to 13 rays. 



//. Dorsal fm short, higher than long; head rather bluntisli, 4^^ in length. 



LABIATUS, 285. 

 hh. Dorsal fin longer than high. 



i. Scales before dorsal about 40; head conical, small, 4J,^ in length. 



OCCIDENTALIS, 286. 



il. Scales before dorsal 31; head larger, 4^;'; in length. 



BERNAIIUINI, 287. 

 (jij. Dorsal fin loug, of about 15 rays, head large, the lips very full. 



MACROCHEILUS, 288. 



ff. Scales in lateral line 58 to 70; lips with about 4 rows of papilla;. 



j. "Nose" little developed, not projecting much beyond the moderate mouth; 

 mandible nearly horizontal. 

 Ti. Dorsal moderate, scarcely higher than long, its base \]/^ to \% in head; 

 the rays 11 to 13. 



I. Mandible 3}^ to ?% in head; upper lip narrow, with usually but 3 to 5 



rows of papillae, the number greater in western specimens (var. 

 snckU'i); scales 10-64 to 68-9, crowded anteriorly. 



COMMEUSONIl, 289. 



II. Mandible 3 to SJ^ in head; upper lip broader, with 4 to 6 rows of 



papillse; scales 9-G3 to 71-9, crowded anteriorly. ardens, 290. 



kk. Dorsal short, distinctly higher than long, its base 1} jj in head, its rays 11 or 

 12; upper lip with 4 to 6 rows of papillai. 

 m. Scales small and crowded anteriorly, 59 in lateral line; fontauelle large. 



GILA, 291. 

 mm. Scales larger, little crowded anteriorly, about 56 in the lateral line, 

 each with a dark spot at base; fontanelle small. 



INSIGNIS, 292. 



jj. "Nose" largely developed, slender and projecting at an angle beyond the 

 profile, its length 2% in head; mouth small, inferior, the lips smoothish; 

 D. 11 or 12; scales G4. (Approaches Chasmistes.) fecundls, 293. 



Hypentelium, (iiTTo, below; nevre, five; lahiinn, lip, "lower lip five-lobed"): 



aa. Head broad, depressed, and transversely concave between orbits; scales nearly equal over 



the body, not crowded anteriorly 48 to 55 in the lateral line; lips very thick; lower 



fins large. 



n. Head large, 4 to 4J^ in length; internrbital space concave. nigricans, 294. 



Jill. Head very small, 5 in length; interorbital space flattish. khothcecus, 295. 



Subgenus CATOSTOMUS. 



279. CATOSTOMUS LATIPINNIS, Baird & Girard. 



(Flannel-mouthed Sucker.) 



Depth 5f in the length. Head moderate, 4| in length, rather slender, 

 with prominent snout and rather contracted, inferior mouth ; outline of 

 the mouth triangular, the apex forward ; lips very thick, greatly de- 

 veloped ; lower lip incised to the base; its posterior margin extending 

 backward to opposite the eye; tubercles on lower lip smaller behind; 

 jaws with a slight cartilaginous pellicle. Eye small, high up; the head 

 flattish above. Scales long and low; ^losteriorly rounded, their horizontal 

 diameter greater than the vertical, 17-98 to 105-17. Body slender and 

 elongate; the caudal peduncle loug and slender. Fins excessively 



