470 GEOLOGICAL SUEVEY OF THE TERRITOEIES. 



Depth, 4.75 in total, (to point caudal;) eye, 5 times in lieadj 

 muzzle acute; scales larger, 26 below dorsal tin; cranium 

 not keeled above; bead one-fourth length; dorsal fin 

 nearer muzzle than end caudal scales ; caudal fin scarce- 

 ly emarginate ; Br. X 8. sjpilurus. 



Head large, broad, flat, not keeled, 4.25 in total, equal depth 

 of body ; muzzle obtuse ; eye nearly 5 times in head ; 

 scales, 42 below dorsal first ray ; dorsal fin equidistant ; 

 caudal fin not notched , 8. stomias. 



Head smaller, 4 times in length to notch of caudal, (which 

 is well emarginate ;) upper surface keeled ; muzzle ob- 

 tuse ; eye 4 times in length ; depth, 4.5 in length, to end 

 caudal scales ; dorsal mlHway between latter and end 

 of muzzle; scales small, 40-43 below dorsal first rayj 

 Br. XE S. pleuriticus. 



Head acuminate, keeled above, 4.66 times in length to notch 

 of caudal fin, which is well marked ; eye, one-fifth head ; 

 depth, 5.25 to caudal notch ; dorsal nearer muzzle than 

 end of caudal scales ; scales large, 33 below dorsal first 

 ray ; Br. XII ; spots large, distant 8. carinatus. 



Head one-fourth total length ; eye, 5 times in head; dorsal 

 fin equidistant between insertion of caudal and end of 

 muzzle ; muzzle rather pointed ; Br." X, XI 8. irideus. 



Of the above species 8almo spiluriis and 8. carinatus are distinguish- 

 able by their large scales and smaller orbits ; while in 8. stomias and 

 8. pleuriticus the scales are very small. On the other hand, 8. carinatus 

 and 8. pleuriticus agree in the strong median carina on the superior 

 aspect of the cranium. 8. stomias is readily separated by the large 

 head and mouth. Its habitat, so far as known, is the Kansas Eiver, 

 far to the eastward of the Eocky Moi;intains.* 



. Salmo spilurus, Cope, sp. nov. 



This species is represented by six specimens from the Sangre de 

 Christo Pass, in Colorado, from one of the sources of the Eio Grande. 



It is rather a fusiform fish, with small head and acuminate muzzle, 

 which is very little decurved at the end to the lip margin. The eye 

 enters the muzzle 1.33 times, the inner border of the adipose eyelid 

 being regarded as the dividing line. The top of the head is slightly 

 convex, but entirely without keel. The maxillary bone extends to a 

 little beyond the posterior margin of the orbit, and. is flat and consider- 

 ably wider distally than it is proximally. In this it differs from the 

 8. stomias, Cope, where that bone maintains an almost equal width 

 throughout. All the teeth are well developed, including both rows of 

 vomerines. Scales in about 33 rows between the base of the first dor- 

 sal ray and the lateral line, or 26 rows between the middle of the dorsal 

 fin and the same. 



Eadii, Br. X ; D. II. 11, (10 in one ;) A. II. 10, (in two, 11.) 



Ground color, i3ale in spirits ; the caudal peduncle from the middle 

 of the anal fin, with the caudal and dorsal fins, thickly spotted with 

 large, irregularly disposed black spots. Those on the caudal peduncle 

 are darkest between the scales ; each one having, therefore, a reticulated 

 appearance. Above the lateral line they extend to the dorsal fin, con- 

 tinually contracting their distribution from the lateral line upward. 



■ * In Hayden's Report, Geology of Wyoming, 1871, pi 433, this is erroneously stated 

 to be the Platte, a very different river. 



