30. CATOSTOMID^E - ERIMYZON. 133 



somewhat inferior ; the upper lip well developed, freely protractile ; the 



lower moderate, infolded, /^-shaped in outline, plicate, with 12-20 plicai 



on each side. Lower jaw without cartilaginous sheath, rather stronger 



than usual, and oblique in position when the mouth is closed, thus simi- 



lar to the mouth of Ictiobns. Eye moderate, rather high up, placed 



about midway of the head. Suborbital bones considerably developed, 



not very much narrower than the fleshy portion of the check below 



them ; the posterior suborbital concavo-convex, about twice as long as 



deep, sometimes divided ; the anterior somewhat deeper than long, aome- 



times divided into two, sometimes united with the preorbital bone, which 



is well developed, and much longer than broad. Opercular bones mod- 



erately developed, scarcely or not rugose. Fontauelle rather large. 



Gill-rakers rather long. Isthmus moderate. Pharyngeal bones weak ; 



the teeth quite small, "slender, and weak, rapidly diminishing in 



length upwards, each tooth narrowly compressed, with a cusp on the 



inner margin of the cutting surface, and some inequalities besides. 



Scales rather large, more or less crowded forwards, sometimes showing 



irregularities of arrangement ; the longitudinal radiating furrows much 



stronger than usual ; the scales rather longer than deep, but so imbri- 



cated in the adult that the exposed surfaces appear deeper than long. 



Lateral line entirely wanting. Scales in the longitudinal series from 



head to base of caudal 35-45 in number ; scales in transverse row from 



base of ventral to dorsal 12-18. Dorsal fin rather short and high, with 



10-14 developed rays, the number usually 11 or 12. Beginning of dor- 



sal fin rather nearer snout than base of caudal. Pectoral fins mod- 



erate, not reaching ventrals ; the latter not to vent. Ventrals under 



a point rather in advance of the middle of dorsal ; their rays normally 



9, but occasionally 8 or 10. Anal fin high and short, more or less 



emargiuate or bilobed in adult males. Caudal fin moderately forked 



or merely lunate, its two lobes about equal. Air-bladder with two 



chambers. Two species known. (Ipi, an intensive particle ; /*uw, to 



suck.) 



. E. ssucella (Lac.) Jordan. Creelc Fisli ; Clnib Suclcer. 

 Body oblong, compressed, becoming gibbous with age, the ante-dorsal 

 region more or less elevated in the adults, the depth 3J in length, ranging 

 from 2$ in adults to 4 in young. Head stout, short, about 4 in length 

 (4-4i), the interorbital space wide and depressed, the lower parts nar- 

 rower. Eye not large, 4^ in head (4J-5 J). Mouth protractile downwards 

 and forwards, the mandible oblique. Scales usually closely imbricated 



