FISHES — SALMONIDAE — SALAU IRIDEA. 



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upon its external margin ; its posterior margin is about the third of the depth of the deepest 

 anterior ray. The ventrals are rather slender and inserted opposite the middle of the base of 

 the dorsal. The pectorals are likewise slender and sub-lanceolate in shape. All the rays are 

 articulated and the majority bifurcated and branched several times. 



Br. 9 : 9 ; D 12 ; ; All; C T, 1, 9, 8, 1, 8 ; V 8 ; P 14. 



The anterior two rays of the dorsal are mere rudiments^ as also the anterior one of the anal. 



The scales are quite small ; on the dorsal region they are sub-elliptical, elongated horizontally, 

 as well as in the lateral line, but there they taper anteriorly, whilst on the abdomen they are 

 deeper than long, sub-quadrangularly rhomboidal, and a little larger than on the dorsal region. 

 The concentric stria are continuous ; the centre of the scales is homogenous and transparent. 



The ground color of the dorsal region is greyish brown with a kind of purplish hue, especially 

 visible along the middle of the flanks ; sub-circular black spots are scattered all over from the 

 head to the tail, where they are much more crowded than on the body ; on the dorsal and 

 caudal fins these spots are likewise numerous and conspicuous ; a few of these only may be 

 observed beneath the lateral line upon the abdominal region ; along the peduncle of the tail 

 they nearly extend to the inferior outline, some of which may even be seen upon the anal fin. 

 Along the middle of the flanks these black spots are surrounded by a light areolae. The 

 inferior region of the body is of a uniform greenish olive or yellow. The head is greyish 

 olive, darker above than upon the sides, with a few black spots upon the tympanic region. 



Specimens of this species were collected by the party under Lieut. Beckwith in Utah creek 

 and at Sangre de Cristo Pass, upper waters of the Rio Grande del Norte (Rio Bravo). 



References to the figures. — Plate LXXIIl, fig. 1, represents Solar virginalis, size of life. 

 Fig. 2 is a scale from the dorsal region. Fig. 3, a scale from the lateral line. Fig. 4, a scale 

 from the abdominal region. Figs. 2 — 4 are magnified views. 



List of specimens. 



3. SALAR IRIDEA, Grd. 

 Plate LXXIII, Fig. 5 ; and Plate LXXIV. 



Spec. Char — Body sub-fusiform in profile, otherwise compressed; head well developed, constituting a little less than the 

 fourth of the total length. Jaws sub-equal; posterior extremity of maxillary extending to a vertical line drawn somewhat 

 beyond the orbit. Anterior margin of dorsal fin equidistant between the extremity of the snout and the insertion of the caudal. 

 Keddi-sh brown above, with numerous and small black spots ; yellowish white beneath. 



Syn. — Salmo iridea, Gibbons, in Proc. Cal. Acad. Nat. Sc. I, 1855, 36. 

 Halmo rivularis, Ayres, in Proc. Cal. Acad. Nat. Sc. I, 1855, 43. 

 Salar iridea, Grd. in Proc. Acad. Nat. Sc. Philad. VIII, 1856, 220. 



The general aspect of the body is sub-fusiform, compressed. The head is sub-conical, rather 

 pointed, and constitutes a little less than the fourth of the total length. The jaws are sub- 

 41 a 



