80 L. Agassiz on the Ichthyological Fauna of Western America. - 
solved, will be, if they all three occur also in the Ohio, whether — 
Ra finesque’s C. niger was the big-mouthed or the small-mouthed 
Bubalichthys. Judging from the figure, given by Dr. Kirtland in 
the Boston Journal of Natural History, vol. v, pl. 19, fig. 2, I be- 
lieve his C. Bubalus to be the small-mouthed species. I myself 
have however only seen one specimen of the big-mouthed spe- 
cies from the Ohio, and that in a rather indifferent state of pres- 
ervation, for which I am indebted to Prof. Baird, and none of the 
small-mouthed species. Should however all three, as is possible, 
occur as well in the Ohio, as in the Mississippi, to avoid introdu- 
cing new —— I would call the big-mouthed species B. niger, 
preserving for afinesque’s specific name,—the small-mouthed, 
13. Bubalus, eieinn for it the name which Dr. Kirtland has 
_ it, even though the species of Ichthyobus must bear the 
sam specific n name, being that originally applied to it by Raf- 
Sosecuib. Tt may be that either my B. Vitulus or my B. Urus is 
identical with Dr. Kirtland’s C. Bubalus, but until I can obtain 
original specimens of his species, this point must remain unde- 
cided, as it is impossible from mere descriptions to institute a suf- 
ficiently minute comparison. ‘he specimen from Osage River, 
I shall call B. Bonasus. 
Compared with one another, these species differ as follows: 
B. niger (the big-mouthed Buffalo) differs from B. Bubalus, (the 
small-mouthed Buffalo) by its larger mouth, opening more for- 
wards, its more elongated body, the first rays of the dorsal rising 
immediately above the base of the ventrals, and its anterior lobe 
being broader, and the anal fin not emarginated ; B. Bonasus 
differs from B. Bubalus and from B. niger in having the mouth 
larger than the first and smaller than the second, and from B. 
Bubalus by its less emarginated dorsal, which renders its larger 
lobe broader, anal fin not emarginated, opercle larger. A farther 
comparison with the southern species could only be satisfactory 
if accompanied by accurate figures. 
I therefore turn now to the genus— 
Ichthyobus, Rafin.* 
In the form and position of the fins, as well as in the general 
outline of the body, this genus is very nearly related to Buba- 
lichthys, but in the structure of the parts of the head, it is quite 
dissimilar. he mouth opens directly forwards, and is large and 
round. The lips are small, smooth and thin; the upper one is 
not thicker than the intermaxillary itself and tapers to a narrow 
dge. At the symphysis of the lower jaw, which is larger than 
in any other genus of this group, the lower lip is hardly more 
than a thin membrane eomree its small lateral lobes. 
Rafines incorrectly Ietiobus; as its name means Bull or 
sul nb oa bes it ue to be eae Ichthyobus, as I have 
already universalis, p. 194. 
