84 FISHES OF PENNSYLVANIA. 

In Pennsylvania a fertile hybrid between the lake and brook trout is held 
in much higher esteem than the lake trout as a food fish. 
Famity PERCOPSID (Tue Trovur Percuss). 
Genus PERCOPSIS Aaassiz. 
95. Percopsis guttatus Agassiz. 
The Trout Perch. 
Body rather long and moderately compressed, covered with thin ctenoid scales; 
head scaleless and without barbels. Gill openings wide. Opercles well developed. 
Gill rakers short, tubercular. Skull highly cavernous; mouth small; the margin of 
the upper jaw formed by the short non-protractile intermaxillaries. No supple- 
mental maxillary bone. Small villiform teeth on the intermaxillaries and mandible. 
The tongue is short, not free at tip. Pseudobranchiz developed. Six branchioste- 
gals. The lateral line is continuous, The first dorsal over middle of body, with 
nine to eleven developed rays. Adipose fin small. The anal and ventral eight- 
rayed. Caudal long, forked. Pectorals narrow, placed high. The stomach is siph- 
onal and with numerous pyloric czeca as in certain Salmonide. The eggs are mod- 
erately large and are excluded through an oviduct. Air bladder present. 
The greatest height of the body is about two-ninths of the total without caudal, 
the head about three-elevenths. The maxilla does not reach to the eye. The lower 
jaw is slightly included. 
Seales in lateral line 47 to 50. 
Color pale olivaceous, the upper parts with rounded dark spots made up of minute 
dots. A silvery median stripe, becoming obsolete in front. Peritoneum silvery. 
The trout perch is a common fish in the Great Lakes and their tribu- 
taries. It ranges north to Hudson’s Bay having been obtained at Moose 
Factory by Walton Hayden, also from Nelson river, near Rock Factory, 
by Dr. Robert Bell. It has been collected in the Delaware river by Dr. 
©. C. Abbott, in the Potomac by Professor Baird, in the Ohio by Drs. 
Jordan, Henshall and Bean, and Dr. Gill has recorded the species from 
Kansas. The trout perch is too small to be valuable for food, but is 
doubtless an excelleut bait. It is one of the most remarkable fishes of 
our fresh waters, combining as it does the characters of the salmon and 
some of the perches. Its name indicates this singular relationship. It 
is voracious, takes the hook freely and spawns in the spring. 
ORDER HAPLOMI. THE PIKE-LIKE FISHES. 
Famity CYPRINODONTID (Tue Kixx1-rrsues). 
Genus FUNDULUS Lacepépr. 
96. Fundulus majalis (Watzavm. ) 
The Striped Killifish. (Figure 51.) 
The body is stout, oblong, not very deep nor greatly compressed. The head is 
contained nearly two and one-half times in the total length without caudal, and the 
depth four times. The snout is moderately long, one and one-half times as long as 
the eye. The eye one-fifth as long as head. The scales are moderately large, those 
