290 HISTORY OF THE FISHES OF MASSACHUSETTS. 



GENUS VI. CATOSTOMUS, LESUETTB. 



Back with a single dorsal fin. Gill-membrane three-rayed. Head and opercula 

 smooth. Jaws toothless and retractile. Mouth beneath the snout, lips plaited, lobed, 

 or carunculated, suitable for sucking. Throat with pectinated teeth. 



CATOSTOMUS BOSTONIENSIS, Lesueur. 



The Sucker. 

 (PLATE XXII. FIG. 3.) 



Ct/prinus calostomus, FOSTER, Mem. Amer. Actul., n. pt. 2, p. 55,'pl. 2, fig. 4. 

 Catostomus Bostoniensis, LESUEUK, Journ. Acad. Nat. Sc., i. p. 106. 



" " STOREE, Report, p. 84. 



Le Catostome Bostonien (Catostomus Bostoniensis, LES.), Cuv. et VAL., xvii. p. 432. 



" " STOBEB, Mem. Amer. Acad., New Series, 11. p. 423. 



" " " Synopsis, p. 191. 



Color. Above of a light-brown ; the sides of a reddish-brown, presenting beautiful 

 metallic reflections ; opercula golden. Head, dark-olive above ; beneath, white. Pupils 

 black, irides golden. The pectorals, ventrals, and anal fin are reddish-yellow ; the 

 dorsal and caudal fins are brown ; the latter fin is the darker. 



Description. Body subcylindrical, elongated ; rounded in front of the dorsal fin, 

 compressed posteriorly ; the dorsum is broad in front of the dorsal fin. The scales on 

 the anterior portion of the body are quite small ; they increase in size towards the 

 posterior portion, and back of the dorsal fin are much larger ; they exhibit at their 

 exposed extremity a few very distinct longitudinal strise, which are crossed by minute 

 concentric lines ; more numerous longitudinal stria3 are seen at the concealed extremity, 

 which is rounded at its centre. 



Head naked ; its length is rather less than one fifth the length of the body. A series 

 of mucous pores extends across the occiput to the gill-covers on each side, and from 

 the termination of this series a second passes forward to the posterior superior angle 

 of the eye, downward back of the eyes, then curves forward and is lost about the snout. 

 Another series passes forward, from the occipital series between the eyes, which 

 extends to the snout. Eyes moderate in size, oblong ; distance between the eyes equal 

 to less than one third the length of the head. Mouth small, very protractile, lips 

 carunculated. Lower lip bilobate. Nostrils double, the anterior quite small, the 

 posterior much the larger and partially covered by a fleshy valve. The lateral line, 

 which seems to be a continuation of the series of mucous ducts upon the head, 



