FISHES OF PENNSYLVANIA. 71 

is a valuable species. The first account of its habits was published by 
Mr. F. C. Gilchrist in Forest and Stream, April 7, 1892. 
Genus THYMALLUS Covovier. 
88. Thymallus ontariensis Cuv. & Vat. 
The Grayling. (Figure 50.) 
The grayling may be readily distinguished from its relatives among the salmon, 
whitefish and trout by its very long and high dorsal, which contains about twenty 
rays. The jaws contain well-developed teeth and the scales are smaller than in the 
whitefishes. The body is oblong, not very deep, somewhat compressed. The head 
is short, its length a little more than one-fifth of the total without caudal, and nearly 
equal to the depth. The caudal peduncle is slender, its depth about one-third the 
greatest depth of body. Mouth moderate, the upper extending to below the pupil. 
A few slender teeth on maxillary, intermaxillary and mandible; a small vomerine 
patch of teeth and palatine teeth present. Tongue toothless or with a few small 
teeth. Seven or eight branchiostegals; gill openings wide; about eleven short, 
slender gill-rakers below the angle of the first arch. Eye from one-third to one- 
quarter as long as head. Distance of dorsal from snout equals one-third of total 
length without caudal ; the dorsal base two-sevenths of total. Dorsal rays shorter 
in front than behind, the longest ray near the end of the fin, equal to length of 
head. The ventral origin is slightly behind the middle of the dorsal; the length of 
the ventral equals that of the pectoral, or about four-fifths length of the head. The 
anal origin is distant from ventral origin a space nearly equal to base of dorsal. The 
longest anal ray equals half length of head. The adipose fin is above the last rays 
of the anal ; this fin is narrow, its width being less than half the length, which is 
but two-sevenths of the length of head. 
D. 24; A. 12; V.9. Scales, 9, 90-94, 13. 
The sides are purplish gray, silvery below. Dorsal with blackish lines alternat- 
ing with rose-colored ones and with green and rose-colored spots. A few small, 
dusky spots on the middle of the sides in front. Ventrals crossed obliquely by 
rose-colored lines. 
The graylings of North America are found in Alaska and the north- 
west territory; in Montana and probably other portions of the Rocky 
Mountain region and in both northern and southern Michigan. The 
Michigan species is not native in Pennsylvania, but was introduced about 
1874 in this state as well as in New York. The Alaska grayling appears 
to me to be sufficiently distinct from the Michigan species to be desig- 
nated under the name by which it was described by Richardson, Thy- 
mallus signifer. 
Dr. Jordan distinguishes a variety of grayling in the Rocky Mountain 
region, Thymallus ontariensis cis-montanus. I have never been able to 
make out more than two species of grayling, the Michigan and Alaskan. 
The Michigan grayling is best known in the Muskegon, Manistee and 
AuSable rivers. The Rifle and the Jordan also have the species, and 
Portage lake in the extreme northern part of the state is said to contain 
it. This fish rarely exceeds sixteen inches in length and a weight of two 
pounds, while the average length is ten or eleven inches and the weight 
one-half pound. 
