202 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY — III. 



outlines soinewbat serrate; lateral line well dc^veloped, nearly straij^bt, 

 with 35 to 12 scales, 12 to 11 iu a cross-series Ironi veiitraKs lo dorsal ; 

 dorsal tin beginning near tbe middle of tlie body, soinewbat in advance 

 of llie ventrals, its anteiior rays elevated, tiieir beigbt about o<iual to 

 ball' tbe bas*; of tbe tin, tbe number of rays in tbe dorsal tin ranging 

 froai 25 to 32; caudal liu well lorUed, tbe lobes about equal, not lal- 

 cate ; anal tin comparatively long and ratiier low, of 8 or 1) develoi)ed 

 rays; ventrals moderate, 10 rayed ; pectorals ratber sbort: sexual i)eiu- 

 liarities, if any, unknown : coloration dull dark brown, nearly plain, not 

 silvery ; fins olivaceous or more or less dusty. 



Air bladder witb two cbambers. 



Size quite large. 



In general appearance, tbe species o( BuhaUchthys heaiv a considerable 

 resemblance to tbose of Carpiodes. Tbe form is, however, coarser than 

 that of any Carpiodes, the dorsal fin is lower, and tbe coloration is 

 darker and duller. Tbe species reach a larger size than do tbose of 

 Carpiodex, but whether larger or not than the species of Ichthyohus I am 

 unable to say. Iu external appearance, BuhaUchthys is intermediate 

 between Carpiodes and Ichthyohus, tbe one species, buholns, resembling 

 Carpiodes most, the other, nrns, being most like Ichthyohus. 



Our knowledge of tbe species of this genus is very incomplete. ]\Iany 

 species were nanu'd and indicated by Professor Agassiz, but witb siu-li 

 fragmentary descriptions that not a single one of them is certainly 

 known by any one. I have, however, been able to identify in specimens 

 from Quincy, 111., tbe fishes termed by him B. hnhalus and B. ni<jer, 

 tbe small mouthed and the large-mouthed liullalo. Assuming these two 

 well-separated species as a basis, I have compared with tlu-in numerous 

 BuUalofisbes from various localities, and in all cases I have found them 

 identical witb either tbe one or tbe other. 1 have therefore adopted 

 the hypothesis, possible, and perhaps probable, that all of the nominal 

 species of Professor Agassiz were based on the one or the other of these 

 two forms. As to this, I may say that tbe sole basis of some of these 

 nominal species was tbe diflerence in locality. From what we know of 

 tbe range of other species of Catostomidw, there is nothing antecedently 

 improbable in tbe same fish being found in tlu' NVabasli and Mol)il(^ 

 Kivers, or ib the Tennessee and Osage. Myxostoma )>iacrokpidotum, 

 Erimyzon ohlongus, Minytrema melaiu}2)8, Catostomus teres, and others 

 are known to occur in all four of those streams. The questions of 

 locality may, I think, be salely eliminated from the discussion. The 



