FISHES—SALMONIDAE—OSMERUS. 
323 
The anterior margin of the dorsal fin being 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 hands may yet be seen along the silvery area of the middle of the flanks. Three rather 
large spots may he 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 Solar 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. 
Catal. 
No. 
No. of 
spec. 
Age. 
Locality. 
When col¬ 
lected. 
Whence obtained. 
Orig’l 
No. 
Nature of 
specimen. 
Collected by— 
594 
1 
Adult. 
Chico creek, Cal.......... 
1855 
Lt. R. S. Williamson.. 
Alcoholic • 
Hr. J. S. Newberry. 
595 
2 
San Francisco, Cal_- - - 
1855 
.do.. 
_do_ 
Dr. W. 0. Ayres. . 
59C 
x 
Humboldt Bay, Cal... 
1854 
Lt. W. P. Trowbridge . 
.'...do_ 
Lt. Trowbridge .. 
597 
6 
A.&Y. 
H’dof San Matteo c’k,Cal . 
1855 
R. D. Cutts, Esq. 
. 
....do.... 
R .D. Cutts, Esq.. 
598 
2 
Petaluma creek, Cal_ 
1855 
Mr. E. Samuels _ 
... do 
Mr. E Samuels . „ 
599 
1 
San Francisco, Cal. 
1856 
Dr. W. 0. Ayres. 
27 
....do.... 
Dr. W. 0. Ayres.. 
% 
OSMERUS, Artedi. 
Gen. Char. —Body 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 aperture? continuous under the throat; branchi- 
ostegals six or eight on either side. 
