304 
U. S. P. R. R. EXP. AND SURVEYS—ZOOLOGY—GENERAL REPORT. 
edges being linear, and would be parallel were the scales not tapering towards their anterior 
concave margin just alluded to. Radiating furrows are observed upon the anterior section only. 
The ground color is olivaceous brown ; the upper aspect of the head, the back, and the sides 
are rather darker, resulting from crowded minute dots upon the scales, which dots are more 
scattered over the flanks. The belly and the inferior surface of the head are unicolor, 
yellowish. A black streak exists upon the middle of the flanks, from the anterior third of body 
to the base of caudal fin, intersected by irregular transverse and elongated spots. 
List of specimens. 
Catal. 
No. 
No. of 
spec. 
Age. 
Locality. 
When col¬ 
lected. 
Whence obtained. 
Nature of 
specimen. 
Collected by— 
938 
4 
Adult. 
San Diego, California.... 
1853 
Lt. W. P. Trowbridge .. 
Alcoholic. 
A. Cassidy. 
Family ESOCIDAE , Bonap. 
The upper arcade of the mouth is formed by tbe premaxillar in front, and the maxilar bones 
laterally. The body is covered with scales. The dorsal fin is situated opposite the anal; no 
adipose fin being present. The pseudo£branchia are glaudulous, not visible, being covered by 
the mucous membrane of the respiratory apertures. The swimming or air-bladder is simple ; 
its inner surface exhibiting a rete mirabile. There are no pyloric appendages and no cul-de-sac 
to the stomach. 
Syn.— Esoces, Cov. Regn. Anim. II, 1817, 182 ; 2d ed. II, 1829 ; ed. illustr. Poiss. 229.— Mull, in Wiegm. Archiv 
fur Naturg. 1843, I, 323; &, 1845, I, 132.—Cuv. & Val. Hist. nat. Poiss. XVIII, 1846, 269. 
Esocidae, Bonap. Sagg. Distr. metod. Anim. Vertebr. 1831, 113.— Richards. Faun. Bor. Amer. Ill, 1836,123.— 
DeKay, N. Y. Faun. IV, 1842, 222.— Storer, Synops. 1846, 184. 
The pikes and pickerels which represent this family are all inhabitants of the fresh waters of 
the temperate zone. The genus Esox is the only one of the family as recently limited by the 
late Prof. Joh. Muller. 
A few specimens of the latter genus were collected, under Lieut. A. W. Whipple, by Dr. 
George G. Shumard, near Fort Smith, Arkansas ; and by H. B. Mollhausen in Coal creek, 
Arkansas, and twenty miles west of Choctaw Agency. A more minute investigation of these 
specimens is temporarily deferred until a larger collection shall enable us to monograph the 
genus, a task which could not be attempted under the present circumstances. 
Family SALMONIDAE^ Bonap. 
In this family the upper arcade of the mouth (upper jaw) is formed anteriorly by the 
premaxillar (intermaxillar bones), and laterally by the maxillaries, the dentition varying 
according to the genera. The body is always covered with scales. There is also an adipose fin. 
Pseudo branchia or accessory gills are present in all. Numerous pyloric appendages may be 
observed. The swimming or air bladder is simple, there being no oviduct; the eggs, upon 
leaving the ovaries, are dropped into the abdominal cavity, whence they find an exit through a 
post-anal aperture provided to that effect. 
