470 GEOLOGICAL SUEVEY OF THE TERRITORIES. 



Deptli,4.75 in total^ (to point caudal;) eye, 5 times in head; 

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

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

 nearer muzzle than end caudal scales ; caudal fin scarce- 

 ly emarginate ; Br. X S. spilurus. 



Head large, broad, llat, 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 , S. 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 midway between latter and end 

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

 Br. XI S, pleiiriticus. 



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 S. carinatns. 



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

 fin equidistant between insertion of caudal and end of 

 muzzle ; muzzle rather jDointed ; Br. X, XI 8. irideus. 



Of the above species Salmo spiliiriis and S. carinatus are distinguish- 

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

 S. pleuriticus the scales are very small. On the other hand, tS. carinatns 

 and S. 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 lar as known, is the Kansas Iliver, 

 far to the eastward of the Kocky JMountains.* 



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 Bio 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 au almost equal Avidth 

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

 vomeriues. Scales in about 'So 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. 



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



•Ground color, pale 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. 



* lu Hay den's Report, Geolo<;y of Wyomiug, 1871, p. 433, this is erroneously stated 

 to be the Platte, a very dijffereut river. 



