GEOLOGICAL SURVEY OF THE TEERITORIES. 471 



A few scattered spots are found all the way to tlie liead, and four or 

 five mark the side of the latter. Adipose fin spotted; others unicolor. 



The largest specimen obtained measures 13 inches in length. 



The affinities of this species to the S. virginaUs appeared to be close, 

 and Girard cites specimens from the locality from which it was procured 

 as belonging to the latter. Its description cannot, however, be recon- 

 ciled with the iS. spilurus^ especiall}^ in the relations of the depth to the 

 length, by which it would appear that S. virginaUs is a much more 

 slender fish. The figure also agrees with the descrijUion. 



Salmo pleuriticus, Cope, sp. noi\; Salmo (SaJar) virginaUs^ Gope, not 

 Girard, (Hayden's Survey Wyoming, 1871, 433.) 



This is the abundant mountain trout of the head-waters of the Green 

 and Platte Eivers, and even of the Yellowstone. It is rather a stout 

 si)ecies, with obtusely descending muzzle, and large eye entering the 

 head only four times. The cranial keel is a marked character; its ele- 

 vation is greater between the orbits than on the posterior part of the 

 frontal bones. The interorbital width is 1.33 times the long diameter 

 of the interpalpebral opening of the eye, The dorsal fin is nearer the 

 origin of the marginal rays of the caudal fin than to the end of the 

 muzzle, but is midway between the latter and the termination of the 

 scales on the sides of the fin. Eadii, D. II. 11-12 and 13 ; A. II. 11. 

 Br. XI. The scales range from 40 to 45 below the first dorsal ray to tbe 

 lateral line. The maxillary bone extends to a little be^'ond the orbit, 

 and is not expanded. 



This is a spotted species, and the spots are chiefly found above the 

 lateral line and on the whole caudal peduncle, and on the dorsal and 

 caudal fins. They are usually rather scattered, less numerous on. the 

 peduncle tha^n in 8. spiluruSj and more so anteriorly ; those on the fins 

 are smaller and less numerous. There is, however, variation in the size 

 and number of the spots. The sides are ornamented with short, broad 

 longitudinal bars of crimson; a band of the same color occupies the 

 fissure within each ramus of the mandible and skin on the median side 

 of it. The fins are all more or less crimson ; but none of these are black- 

 bordered. The largest specimens are 10-12 inches long. 



Seven specimens of this species are in the collections from the heads 

 of Green Eiver ; from JMedicine Lodge Greek, Idaho, (two specimens ;) 

 four from the Junction, Montana. A specimen each from Yellow Greek 

 and the Gallatin Fork of the Missouri, Montana, represent at least a 

 color variety or this fish. The spots are much smaller and much more 

 numerous, though distributed over the same regions ; they are less 

 numerous on the caudal fin. In the Gallatin specimen there are 51 

 scales above the lateral liue ; in the other 44. Another variety from 

 the Yellowstone Basin is only re|)resented by young specimens. They 

 have no spots on the caudal fin. 



A number of dried specimens from the Yellowstone Lake, of larger 

 size than the specimens above described, x^robably belong to this species. 

 They are rather more closely si)Otted on the caudal peduncle and fin, but 

 are similar in all important respects. The only discrepancy which I find 

 is the relatively smaller eye, (not orbit,) which entei'S the head five times, 

 and the gieater prolongation of the maxillary bone. These characters 

 are, i)erhaps, due to the larger size attained by the individuals. They 

 are from a foot to eighteen inches in length. 



Salmo carinatus, Gope, sp. nov. 

 The characters of this species, pointed out iu the table, show its marked 



