308 



U. S. p. R. R. EXP. AND SURVEYS — ZOOLOGY — GENERAL REPORT. 



teeth occupy nearly the whole length of the hone. On the vomer the teeth are but few and 

 less conspicuous than any of those above mentioned. The lingual teeth, three in each series, 

 are nearly as large as on the lower jaw. The eye is well developed, sub-circular in shape, its 

 horizontal diameter being contained about five times in the length of the sides of the head. 

 The vertical diameter of the opercle is nearly one-third more than the transversal ; that bone 

 is broader inferiorly than superiorly. The sub-opercle is half the size of the former. 



The scales are small, sub-elliptical in their horizontal diameter, and imbricated so as to 

 conceal half of their surface. The lateral line is formed of very conspicuous tubes, and runs 

 along the middle of the flanks, from the thoracic arch to the base of the caudal, in a nearly 

 straight line. 



The color, we venture to say, is very much altered on the specimen before us. The upper 

 regions seems to indicate a ground of a bluish grey, becoming lighter along the sides, and 

 still more so under the abdomen. Over the sides are. distributed spots of a yellowish hue in 

 the shape of large drops scattered all over from head to tail. Whether these spots extended 

 over the head and fins we are at a loss to know under the present circumstances. 



Ste. Mary's Mission, where the specimen here described was collected, is situated in the 

 Flathead valley, upon the upper tributaries of the northern branch of the Columbia river. 



List of specimens. 



\ 



PARIO, Valenc. 



Gen. Char. — Possesses all the characters of the salmons, differing from the latter by the presence of but one row of teeth 

 upon the shaft of the vomer. The rest of the bones forming the upper roof of the mouth being toothless. 



Syn.— Forio, Valenc in Cud. ^ Val. Hist. nat. des Poiss. XXI, 1648, 277.— Grd. in Proc. Acad. Nat. Sc. Philad. VIII, 

 1856, 218. 



The species of this genus are apparently more numerous in North America than in the Old 

 World. The "salmon trout" and the "common trout" of the settlers of Oregon are 

 examples of this group. The European "lake trout" belongs to this same type. 



1. FARIO AURORA, Grd. 

 Plate LXVIII. 



Spec Chak.— Body fusiform, compressed ; head forming tlie fourth of the total length, caudal fin excluded. Upper jaw 

 longest. Maxillary gently undulating ; its posterior extremity extending to a vertical line pa.'sing considerably behind the 

 entire orbit. Anterior margin of dorsal fm equidistant between the tip of the snout and the base of the caudal. Ground color 

 greyish silvery above ; sides and belly yellowish orange ; dorsal fin spotted. 



Stn. — Fario aurora, Grd. in Proc. Acad. nat. Sc. Philad. VIII, 1856, 218. 

 Salmo aurora, Grd. MS. 

 Red char, Lewis St, Clark. 



The specimens upon which our description is based measures something over eleven inches in 

 total length. The body is compressed and the back rounded ; the greatest depth, taken in 



