24 FISHES OF PENNSYLVANIA. 

29. Ictiobus cyprinus (Le Sveor). 
The Quill Back. 
The quill-back is robust, somewhat compressed, with an arched dorsal profile. 
The depth of the body equals one-third of the length; and the length of the head is 
contained three and one-half times in the standard body length. Eye slightly more 
than five times in lengih of head. Length of dorsal base slightly more than depth 
of body. This fin originates a little in advance of middle of body. Its first rays very 
high, the third two-thirds length of longest, thence gradually decreasing in length. 
D. 25; A. 8; V.10. Scales, 6-43-5. Described from No. 33,073, United States National 
Museum, nine inches long, from Havre de Grace, Maryland. 
This is called the carp sucker, silvery carp sucker, quill-back, skim- 
back, spear-fish, sail-fish and carp. As now limited, its range is stated 
to be from Pennsylvania to Virginia, and its center of abundance the 
region about Chesapeake Bay. Prof. Cope also recognized it as occur- 
ring in the Allegheny river and generally throughout the Ohio valley. 
The best account of the food of this fish is given by Prof. S. A. 
Forbes, who records the fish from the large rivers of Illinois and their 
principal tributaries, also from Lake Michigan and small lakes of north- 
ern [llinois. He found it abundant in the lakes and ponds of the river 
bottoms, and less common than other species of carp suckers in running 
water. The species consumes less vegetation than the other fishes of 
its genus, and more mud is mingled with its food. It devours fewer of 
the large insect larvee, and no pond snails. “Mollusks made about one- 
fourth of the food—all the thin-shelled Spheriwm. Insects averaged 
about one-third, and Hntomostraca made nearly one-fourth.” No worms 
or polyzoans were observed, but occasionally protozoa were noticed. 
This species reaches a length of one foot. 
Genus CYCLEPTUS Rarinesque. 
30. Cycleptus elongatus (Lr Svervr). 
The Black Horse. (/.gure 29.) 
The black horse has an oblong, elongate, somewhat compressed body, very small 
head, long caudal peduncle anda forked tail. The greatest depth of the body is at 
the origin of the dorsal fin, and is one-fourth of the standard length ; the length of 
the head is one-seventh length of body. The eye is small, being contained three 
times in its distance from tip of snout. Mouth small; the upper lip is thick and has 
several rows of tubercles, the lower lip not so thick and deeply incised behind. The 
pharyngeal bones are strong, with stout, wide-set teeth, which increase in size down- 
ward. 
The tins are large; the pectoral falcate ; first three rays of dorsal high, the rest 
low ; its base is considerably more than one-third length of body; anal very short. 
The scales are of moderate size, equal all over the body. D. 30; A.8; V. 10. Scales, 
9-62-9. Lateral line perfect, almost straight. The specimen described is No. 10,790, 
United States National Museum, from Ohio; length ten and one-half inches. 
This is known as the black horse, Missouri sucker, gourd-seed sucker 
