FISHES OF THE SANTEE BASIN. 17 



valent to the subgeneric section of Alburnops or "Hybopsi*", called 

 Hudsonius by Girard. 



Body elongate, but compared with its immediate relatives, hudsonius^ 

 amaruSj and storerianus, short aud thick ; moderately compressed, the 

 depth 4J in length : caudal peduncle shortened, 4f in length : head large, 

 4 times in length, relatively heavy and gibbous forward, the snout 

 rounded in profile, as in A. hudsonius. Eye large, rather wider than 

 interorbital space, about equal to snout, 3J in head. 



Mouth moderate, subinferior, the maxillary not reaching to eye. 



Scales large, thin, and loose, 5-39-3, about twelve in front of the dor- 

 sal tin. Lateral line somewhat decurved in front. 



Fins moderately developed. Dorsal beginning in advance of ventrals, 

 I, 8 ; its first ray nearer snout than caudal. Anal I, 8, rather small. 

 Pectorals not reaching to ventrals, the latter not to vent. 



Color clear olivaceous, nearly white, like the rest of the group, some 

 specimens showing a faint plumbeous lateral line. 



Teeth 1, 4-4, 1, two or three of the principal row obtuse, not hooked ; 

 only one or two of the* teeth usually showing a masticatory face. 



Habitat. Abundant in Saluda River, where it reaches a length of 

 about four inches. Also obtained by Professor Cope from the Gatawba. 



The peculiar characters of this species have been noticed by Pro- 

 fessor Cope, who, however, was disposed to consider it a variety of 

 H. amarus. It differs from our specimens of what we consider to be 

 the latter species (from Octnulgee Eiver) in the smaller eye, the thicker 

 head, shorter, deeper body, more decurved front, and shorter caudal 

 peduncle. In amarus, the eye is 3 in head, the head 4J in length, and 

 the caudal peduncle 3|. 



We have been disposed to unite, under the generic name Luxilus, a 

 large number of species forming a series the extremes of which bear 

 little resemblance to each other or to the means, but which form a chain 

 so unbroken that it is difficult to draw any generic lines among them. 

 That this group may ultimately be broken up into natural genera is very 

 probable, but the groups thus far proposed have not received very 

 satisfactory definition. 



These species agree (a) in the absence of any special modification, 

 either of mouth, fins, or alimentary canal; (b) in the dentition, the 

 teeth being in one or two rows, always four in the principal row of 

 the raptorial type, and some or all of them provided with a grinding 

 surface ; often, and in some species always, one edge of the masticatory 

 Bull. N. M. No. 122 



