PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 81 



The scales in CHstivomer are quite small, and the species are gray- 

 spotted. There are probably but two species, Cristivomer namaycush* 

 (Walbaum) and Cristivomer siscowet (Agassiz). 



The species of SalveUnus known within the limits of the United 

 States are compared below. The species from British America, Salve- 

 Unus stagnalis (Fabricius) (= S. nitidus and S. alipes Rich.), S. rossi Rich., 

 S. hoodi Rich., S. lordi Giinther, S. arcturus Giinther, and S. tudes Gope, 

 I have not seen. Most or all of them are probably valid. SalveUnus 

 bairdi, of the Pacific coast, is very near SalveUnus fontinalis, and may 

 be a variety of it ; but never having seen it in life, I am not by any 

 means prepared so to consider it. 



Common characters .-—River Salmon, not anadromous, with the vomer boat-shaped, some- 

 what carinate below; a few teeth on the posterior part of the chevron; none 

 on the depressed shaft: scales very small, more or less imbedded in the skin, 

 in 200-250 transverse series, those of the lateral line considerably enlarged . 

 fius moderate, the last ray of the dorsal not lengthened, shorter than any of the 

 other developed rays ; caudal fin rather short, usually but little emargiuate in 

 the adult, forked in the young : sides of the body with rouud red spots ; lower 

 fius with a pale marginal band anteriorly, succeeded by a darker baud ; in sea- 

 run specimens, these spots and other markings are often obliterated, and a 

 more or less uniform silvery tint prevails : species not of the largest size, the 

 sexual peculiarities not very strongly marked, the adult male usually with a 

 fleshy projection at the tip of the lower jaw, which fits into a slight emargi- 

 nation of the upper jaw. 

 a. Hyoid bone provided with a median band of teeth. 

 b. Body elongate, slender, considerably compressed, the depth about .20 of the 

 length of the body: caudal peduncle long and slender: head quite small, .21 

 of length of body; its upper surface flattish, .13^ of length, the interorbital 

 space about .07 : mouth quite small, the maxillary short and moderately 

 broad, .OS of length, not extending to the posterior margin of the eye; man- 

 dible .12 of length ; snout, .05 : scales quite small, in about 230 trausverse 

 rows: caudal fin well forked; adipose fin rather small: coloration dark blue, 

 the red spots confiued to the sides of the body, round, smaller than the pupil : 



hyoid teeth numerous, small. Lakes of Maine OQUASSA.t 



bb. Body stout, not greatly compressed, the back elevated, the depth .24 of the 

 length: head large, stout, broad, and flattened above, about .28 of length, its 

 upper surface .17 of length, the interorbital space .08 : mouth large, the max- 

 illary extending beyond the eye .11 of length ; the mandible, .16 ; the snout, .07 : 

 hyoid bone with very few (3 or 4), rather strong teeth (sometimes deciduous): 

 fius short, the caudal slightly forked ; adipose fin unusually large, its length 

 in adults nearly twice that of the eye : scales very small, in about 240 trans- 

 verse rows : red spots on the sides quite large, about the size of the pupil ; 

 back covered with very distinct spots, similar to those on the sides, but rather 

 smaller, the dorsal spots said to be cream-colored or greenish in life, rather 

 than red. Streams west of the Sierra Nevada spectabilis. 



* Namaycush Salmon, Pennant. — Sahno namaycush Walbaum, 1792, = Salmo namaycush 

 Bloch, 1801,= Salmo pallidus Rafinesque, 1817, = Salmo amethystus Mitchill, 1818, = Salmon 

 confinis DeKay, = Salmo symmetrica Prescott, 1851, = Salmo adarondacus Norris, 1^64, = 

 Salmo ioma Hamlin, 1863. 



t SalveUnus oquassa (Girard) Gill & Jordan. — Salmo oquassa, Girard, 1854. 

 Proc. Nat. Mus. 78 6 August 6, 1 878. 



