314 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY - IV. 



truiicalux Suckley, Ann. Lye. Nut. Hist. N. Y. 1838, 3: Salmo yainlncri Richardson, 

 Fauna ISnr.-Amer. iii,22l: Sal mo </air<lfri Snekley. Mnnogr. Salmo, 114: Salmo trun- 

 1-tdnx (iiinthcr, vi, 1^2: Salmo tjuirdinri CJintflicr, vi, llrt.) 



bb. Smlrs small. lii."--J(i."> in a longitudinal sevii s. 



(/. Caudal liu truncate or double-rounded, not at all forked in the adult. 



5O7. S. spilliriis Cope. Ilio Grande Trout. 



Body elongate. Head heavy, but proportionately short, its upper 

 surface considerably decurved ; interorbital space transversely convex, 

 obtusely cariuated; the head more convex thau in any other of our 

 species. Mouth very large, the maxillary reaching far past the eye. 

 Teeth on vomer in two distinct series. Dorsal fin low in front, high 

 behind, the last ray more than two-thirds the height of the first; last 

 ray of the anal rather long ; caudal with its middle rays about as long 

 as the others. Profusely spotted; back and sides with round black 

 spots, the spots most developed posteriorly, few on the head, most nu- 

 merous on the caudal and adipose fin; sides with pale blotches. Head 

 3J; depth 4. D. 11; A. 10; scales 37-170-37. L. 30 inches. Upper 

 Bio Grande and Basin of Utah, frequenting mountain streams. 



(Cope, Haydeii's Geol. Surv. Mont. 1871, 470, 1872; Jordan, PLOC. U. S. Nat. Mns. i, 

 74.) 



Var. g>lciiriticus (Cope) Jor. 



A more abundant and much more widely distributed form, having 

 the head and mouth equally large, but the top of the head less convex, 

 the median carina being more marked, especially in the young. The 

 scales are definitely smaller (39-200-40) and the coloration is rather 

 darker. This form abounds in all suitable streams from the Bio 

 (irande, through the Basin of Utah. Specimens intermediate between 

 and pli'itrlticm occur. 



ii pltiii-itirnx Cop' 1 , Ilavden's Gcol. Surv. Mont. 1871, 471, 1872; Jordan, Proc. 



. Nat. Mus. i, 74, lo7H.) 



aa. Hyoid lionc with a narrow hand of small teeth (easily scraped oil' and very often 

 naturally deciduous, especially in old examples). 



5OK. S. ]>lirilir:itus I'allas. V,,I,H<IH Tnnil of the Columbia ; Yt-llowntone Trout; 



I'.rnnl: 1'nnil ; /./,r Trout. 



Body moderately elongate, compressed. Head rather short. Mouth 

 moderate, the maxillary not reaching far beyond the eye. Vomerino 

 teeth as usual, set in an irregular /igxag series; teeth on the, hyoid 

 bone normally present, but often obsolete, especially in old examples. 

 Dorsal iin rather low; caudal tin slightly forked, less so than in tri<l<UN, 

 more than in ,s/;///w (the caudal more iorked in young individuals 



