SUCKLE Y MONOGRAPH OF THE GENUS SALMO. 151 



38. SALMO NAMAYCUSH, Pennant. 



MACKINAW TROUT ; GREAT LAKE TROUT. 



Syx. — Tlie Xamat/citsh salmon, Prxxaxt, Arct. Zool. Snppl., ii. p. 139, 1792. 



Salmo amethysius, Mitchill, Joiiiii. Acad. Sc. Pbil., vol. i, p. 410 ; Dk- 



IvAY, Nat. Hist. State of N. Y., Fishes, p. 240, PI. Ixxvi ;— StoiU':i:, 



Synop. 184(5, p. 193. 

 SaJmo namai/ciish, Kich, F. B. A., vol. 3, p. 179, PI. 79 and 85 ; — Kirt- 



LAXD, Report on the Zool. of Ohio, p. 195. — Boston Jonrn. N. Hist., 



1842, iv, p. 25, PI. 3, fig. 2 ;— Agassiz, L. Snperior, p. 331, Bost. 1850. 

 Salar namayeiish, Valexciexx^es, Cuv. & Val., H. N. Poissous, xxi, p. 



348, 1848. 



Sp. Ch. — I Drawn up from DeKay's description and the examination of 

 specimens in the Smithsonian Institution collection.] Body robust ; 

 dorsal outline moderately arched. Lateral line nearly straight. Scales 

 small, oval, adherent. Head one-fourth of total length. Nostrils double ; 

 contiguous muzzle somewhat pointed. Mouth large. Jaws strong ? in the 

 male, (when worn out;) the upi^er are longest, the lower having a conical 

 point at their tip ; jaws and tongue with a single row of 4eeth on each 

 side ; vomer with but a single row. Teeth strong, sharp, translucent ; 

 in the breeding season showing a beautiful amethystine color at their 

 bases. Dorsal fin nearly in centre of fish ; its height slightly longer than 

 base. 



Rays.— Br. 12: D. 12-14: P. 15: Y. 9-10: A. 11-13. Pectorals low 

 down, pointed. Caudal strongly forked. Length from 2 to 5 feet. 



Colors. — Dark or dusky brownish-gray above: chin and under parts 

 light-ash or cream-color. Back and sides specked with numerous irregu- 

 larly-shaped spots of lighter gray, brown, or soiled- white. Lower fins 

 slightly yellowish. 



Diagnosis. — From S. sislcowef, by its pointed snout and chin; by its 

 more deeply-forked tail; by the difference in the style or pattern of its 

 markings ; its larger size and larger head, which in this species is con- 

 tained four times in the total length, while that of the siskowet nearly 

 five. In the specimens examined by the writer, the teeth of the namay- 

 cush appear to rake backward more. From all other lake-trout it may 

 be distinguished by its great size. 



Hab. — Lake Hnron, Lake Michigan, Lake Superior, and, according to 

 Eichardsou, all the great lakes which lie between the United States and 

 the Arctic Sea ; but never found in tidal waters. 



Only two specimens* of this fi.sh are contained in the Smithsonian col- 

 lection — both young, the largest about 20 inches long. These possessed 

 a few teeth in a cluster at the anterior extremity of the vomer, and then 

 a few scattered in a single row along its shaft, for half its length. But 

 a single row of labial teeth. Sir John Richardson mentions a double 



* Full collections at date of publication. 



