No. VI.] 



NOTICES OF THE FISHES. 



717 



Catastomus Hudsonius. 



Grey Sucker.— Of the English fur Traders. Carpe Blanche, Of the Canadian Traders. Namaypeeth. Gree 

 Indians. 



Genus Cyprinus, L. Catastomus. Le Sueur. Sub-genus JLeuciscus, Les Abies, Cuv. Reg,. Animal, ii.p. 195. 

 Cyprinus Catastomus, Forster Philosoph. Trans. Ixiii. p. 158. t. vi. 

 Namay-peeth and Sucker, Pennant's Arct. Zool. Introd. p. ccxcix. and vol. ii. 402. 

 Catastomus Hudsonius, Le Sueur Journal of Acad, of Sciences, Phil. vol. i. p. 107. 



The body swells gradually from the head until it attains its greatest girth, about 

 half way to the dorsal fin : from thence it tapers to the lower edge of the anal fin, 

 and the remainder of the tail is nearly linear. Its sides and back are slightly 

 flattened, the depth exceeding the transverse diameter rather more than one half. The 

 lateral line runs downwards from the nape of the neck by the side of the gill- 

 opening until it becomes nearly equidistant from the back and belly ; it then runs 

 straight towards the tail, and when it arrives over the anal fin, is reflected 

 upwards at a very obtuse angle, thus giving to the tail a direction differing, though 

 in a slight degree, from that of the body. 



The colour of the back and sides is bluish-grey with a slight tinge of yellowish-red, 

 and considerable lustre. The belly is pearly white. The thoracic and ventral fins 

 are of an ochre-yellow colour tinged with red. The anal is flesh-red and the dorsal 

 and caudal are bluish-grey. 



The scales are for the most part broadly oval, or nearly orbicular and of a medium 

 size. The uncovered portion of each scale is marked with radiated lines, corre- 

 sponding to obscure crenae on the edges, and has a transverse diameter considerably 

 greater than the longitudinal one. The scales on the belly are smaller. They become 

 larger towards the tail. 



The head is smooth, flattened laterally and on the vertex, or it is sub-quadrilateral, 

 convex before the eyes and ending in an obtuse snout. The breadth of the head at 

 the occiput exceeds that of the shoulders, but it gradually decreases towards the 

 nose. The operculum is nearly thrice the size of the sub-operculum ; and it exceeds 

 the other two bones of the gill-covers nearly in the same proportion. Their edges 

 unite to form a smooth segment of a circle, which is edged narrowly with membrane. 

 Various porous lines and tubercles are, as M. Le Sueur remarks, very evident in the 

 dried specimens, but not conspicuous in the recent fish. The figure of Forster having 

 been taken from a dried specimen, conveys on this account a very imperfect idea of 

 the appearance of the head. The head is three times and a half as long as the body 

 from the gill-openings to the caudal fin. The brain is protected by a piece of car- 

 tilage, which, on maceration or boiling, drops out, leaving a rectangular foramen in 

 the cranium, one inch long and a quarter of an inch wide. 



The eyes are oval and placed about their own length nearer to the gill-openings 

 than to the snout. 



