314 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY IV. 
irituvalnn Siickley, Ann. Lyc. Nat. Hist. N. Y. 18.58, 3: Salmo gairdncri Riolianlson, 
Fauna Bor.-AnuT. iii, “2'il: Sahno (jairdneri Snckl(?y, Monogr. Salmo, 114: Halmo b un- 
catuv Giintlier, vi, IxJi: iSalinu gairdiicri Giinthor, vi, ILi.) 
bb. Scales small, ICm-JOG in a longitmlinal series. 
d. Caudal lin trnncato or donblo-ronmled, not at all forked in the adult. 
507. S. S|;>a9cit’ias Cope. — Ilio Grande Trout. 
Jlexly (.‘loiigato. Head heavy, but proportionately short, its up])er 
surface considerably decurved; interorbital space transver.sel}’ convex, 
obtu-sely earinated; the head more convex than in any other of our 
species. 31outh very large, the maxillary reaching far past the eye. 
Teeth on vomer in two distinct series. Dorsal lin low in front, high 
behind, the last ray more than two-thirds the height of the lirst; 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 lin; sides with i)ale blotches. Head 
3.^; depth 4. ]>. 11; A. 10; scales 37-170-37. L. 30 inches. Upper 
liio Grande and Basin of Utah, frequenting mountain streams. 
(Cope, Haydeu’s Geol. Siirv. Mout. 1871, 470, 1872; Jordan, Pioc. U. S. Nat. Miis. i, 
74.) 
A"ar. (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 (30-200-40) and the coloration is rather 
darker. This form abounds in all suitable streams from the Ilio 
Grande, through the Basin of Utah. Specimens intermediate between 
% 2 )ihinis and pleurlticus occur. 
(Salmo 2 )Ieuriticus Cope, Hayden’s Geol. Surv. Mont. 1871, 471, 1872; Jordan, Proc. 
U. S. Nat. Mus. i, 74, 1678.) 
aa. Hyoid bone Avitb a narrow band of small teeth (easily scraped off and very often 
naturally deciduous, especially in old examples). 
50§. S. Pallas. — Salmon Trout of the Columbia; Yellotcslone Trout; 
lloekij Mountain Brook Trout ; Lake Trout. 
Body moderately elongate, compressed. Head rather short. Mouth 
moderate, the maxillaiy not reaching far beyond the eye. Yomerino 
teeth as usual, set in an irregular zigzag series; teeth on the hyoid 
bone normally present, but often obsolete, especially in old examples. 
Dorsal lin rather low; caudal lin slightly forked, less so than in iridcus, 
more than in S 2 )ilurus (the caudal more forked in young individuals 
