PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM, 503 
GENUS HYBOGNATHUS, Agassiz. 
29. Hybognathus argyritis, Girard. (No. 27,431.) 
Hybognathus argyritis, GIRARD, Pac. R. R. Surv. vol. x, 235; Proc. Acad. Nat. 
Sci. Phila. 1856, 182. 
_ Specimens.of this species were seined in Horsehunter Creek at Macon, 
and in the Chickasawha River at Enterprise. Some of these have a 
total length of 45 inches. 
GENUS ALBURNOPS, Girard. 
30. Alburnops taurocephalus, Hay, sp.nov. (No. 27,439.) 
This very interesting species resembles much Hyborhynchus notatus, 
and therefore recalls strongly Professor Cope’s description of IZybopsis 
tuditanus, from Northern Indiana. (See Trans. Amer. Phil. Soc. 1869, 381.) 
It is a true Hybopsis, or Alburnops, as indicated by the short alimentary 
canal and the close union of the spinous dorsal ray to the first soft dor- 
sal. The teeth are 4-4, hooked, compressed, and provided with a masti- 
catory surface. 
The body is stout, somewhat compressed, broad and flat above, with 
a deep and angulated caudal peduncle. The latter is contained in the 
body about 32 times. Its depth is one-half its length. The heed is 
broad and flat above, and at the temporal region forms an angle with 
the cheeks. The breadth of the head behind the eyes is equal to the 
distance from the muzzle to the back of the orbit, and nearly two-thirds 
the length of the head. The muzzle is broad and obtuse; but not so 
truncate as that of Hyborhynchus notatus, since the profile rounds grad- 
ually into the snout. 
The mouth is rather small, horizontal, and terminal ; the jaws about 
equal, the upper heavy. The maxillary hardly reaches a perpendicular 
from the anterior margin of the orbit. Eye large,34 in thehead. Head 
in the length, exclusive of the caudal, 45 times. Depth about equal to 
the length of the head. 
Dorsal I, 8; A. I, 7. The dorsal begins above the ventrals, is longer 
than high, and has on the anterior rays, rather below the middle, a 
black spot. This fin commences nearer the snout than the caudal. The 
anal is small. 
The scales along the lateral line are rather large and silvery; the 
formula is 8-43-4. The scales in front of the dorsal fin are small, 
especially on the nape. 
In color this species is pale yellow, with a dusky tinge given it by 
numerous black punctulations on each scale. The sides are silvery, as 
are also the cheeks and opercles. There is an obsolete dusky band 
along the lateral line, terminating at the base of the caudal in a small 
but distinct black spot. The top of the head and snout brown. 
Length of the largest specimen 3 inches, exclusive of caudal. 
