FISHES — SALMONIDAE — OSMEKOS. 



323 



The anterior margin of the dorsal fin heing equidistant between the insertion of the caudal and 

 the extremity of the snout. The dorsal fin itself is narrower and higher than in the male. The 

 adipose, also, holds the same relations to the anal, and such is the case with the ventrals towards 

 the dorsal. 



The pattern of coloration is very similar in both sexes ; in the female now under consideration 

 the dorsal region is greyish blue and green, the middle of the flanks being silvery white, and 

 the abdominal region olivaceous. The head, upper region of the body, and upper fins, spotted 

 as in the male, perhaps more densely, and also a little further below the lateral line. Transverse 

 dark bands may yet be seen along the silvery area of the middle of the flanks. Three rather 

 large spots may be observed, two on the opercle and one upon the subopercle. 



Specimens were collected in the head waters of San Matteo creek, California, by R. D. Cutts ; at 

 Petaluma, Sonoma county, California, by E. Samuels ; near Humboldt Bay, by Lieut. W. P. Trow- 

 bridge ; and, finally, specimens obtained from Dr. Ayres, of San Francisco, under the name of 

 Salmo rivularis, proved identical with Salmo iridea of Dr. Gibbons. Dr. Gibbons' description 

 was made from a very immature specimen, but has the priority over Dr. Ayres' appellation. 



References to the figures — Plate LXXIII, fig. 5, represents the female sex of Salar iridea, 

 size of life, collected in San Matteo creek. 



Plate LXXIV, fig. 1, represents the male sex of Salar iridea, somewhat reduced in size, from 

 Chico creek. 



Fig. 2 is a scale from the dorsal region, midway between the lateral line and the dorsal fin. 



Fig. 3, a scale from the lateral line. 



Fig. 4, a scale from the abdominal region, midway between the lateral line and the insertion 

 of the ventral fins. 



Figs, 2 — 4 are magnified views. 



List of specimens. 



OSMERUS, Artedi. 



Gen. Char, — Rody elongated, sub-fusiform in profile, tapering posteriorly, terminated by a furcated caudal fin, and covered 

 with well developed scales. The anal fin is opposite the adipose. Ventrals inserted under the anterior margin of the dorsal or 

 posteriorly to it. Head elongated and tapering anteriorly. Mouth rather deeply cleft. Premaxillar'teeth small and curved ; 

 maxillar teeth still smaller ; vomerine teeth large, conical, and placed so much forwards that they appear as though inserted 

 upon the jaws. A row of teeth may be observed along the external margin of the palatines, and another upon the internal 

 margin of the pterygoidians. Tongue provided with large teeth also. Branchial apertures continuous under tlie throat ; branchi- 

 ostegals six or eight on either side. 



