FISHES. OF PENNSYLVANIA. 57 



and fewin number. A straight and well-developed lateral line. Belly without 
scutes. No adipose fin. Dorsal fin over the caudal part of the vertebral column. 
Anal long and low. Ventrals large. Caudal deeply forked. Stomach horseshoe- 
shaped, with blind sac. Intestine short. One pyloricappendage. Air bladder large 
and simple. The eggs fall into the abdominal cavity before exclusion. 
76. Hiodon alosoides Rarinesqur. 
The Northern Moon-eye. (Figure 44.) 
Body deep, much compressed, its greatest depth equalling two-sevenths of the 
total without caudal. The head is short, containing the length of the eye about 
three and one-half times, and equalling a little more than one-fifth of the total with- 
out caudal. The snout is very blunt, the mouth large and oblique, the maxilla 
reaching beyond the middle of the eye. There is a well-developed keel along the 
entire length of the belly. D.9; A. 32; scales, 6-57-7. The general color is bluish, 
silvery on the sides, with golden reflections. 
The northern moon-eye is found from the Ohio river throughout 
the Great Lake region to the Saskatchewan. It is very common in 
Manitoba and other parts of British America. In Pennsylvania it is 
limited to the western region. It is very readily distinguished from 
the other species of the genus by its short dorsal fin, which contains 
only nine rays. It grows toa length of about one foot. The flesh is 
not greatly esteemed, but it is a beautiful fish, and has excellent game 
qualities. 
77. Hiodon tergisus Lez Sueur. 
The Moon-eye. 
The shape of the body is similar to that of the northern moon-eye. The belly has 
a slight, but obtuse keel in front of the ventrals and is compressed to a rather 
sharp edge behind the ventrals. Head short, its length two-ninths of total without 
caudal ; the eye much longer, about one-third length of head. The greatest depth 
of the body is nearly one-third of total length. The pectoral is as long as the head 
without the snout; the ventral not much more than two-thirds length of head; its 
origin is under the eighteenth scale of the lateral line. The anal origin is under the 
seventh developed ray of the dorsal. The longest anal ray is less than one-half 
head. The anal base is as long as the head ; its last ray is less than one-half longest 
Yay. The anal has a deep notch. The longest dorsal ray is little more than length 
of dorsal base. The last ray is not much more than one-half longest. The caudal is 
deeply forked. 
D. 12; A.28 to 32. Scales 6-58-8. 
Upper parts greenish in life, the sides and abdomen brilliant silvery. 
This species is called moon-eye, toothed herring and silver bass. It 
is found in Canada, the Great Lake region and the upper part of the 
Mississippi valley, being very common in large streams and lakes. It 
abounds in Lake Erie and the Ohio, and is seined in large numbers. 
This species grows to a length of one foot and, like the other, although 
a beautiful fish and possessed of excellent game qualities, its flesh is full 
of small bones. It is a good fish for the aquarium. It will take a min- 
now or the artificial fly very readily and the utmost skill is required in 
its capture. Its food consists of insects, small fishes and crustaceans. 
