334 
U. S P. R. R. EXP. AND SURVEYS—ZOOLOGY—GENERAL REPORT. 
1. ENGRAULIS MORDAX, Grd. 
Spec. Chau. —Body slender, elongated, and sub-fusiform in profile. Head constituting the fourth of the total length ; snout 
sub-conical. Posterior extremity of maxillar bone extending to the sub-opercle. Eye large and sub-circular; its diameter 
entering four times and a half in the length of the side of the head. Anterior margin of dorsal fin nearer the insertion of the 
caudal than the tip of the snout. Base of anal fin entering a little over seven times in the total length. Vent situated 
opposite the base of last ray of dorsal fin. Ventral fins small, their tips not reaching the vent. Pectorals rather short, posteriorly 
truncated. Deep bluish brown above ; silvery beneath. 
Syn. — Engrauli •> mordax, Grd. in Proc. Acad. Nat. Sc. Philad. VII, 1854, 138 ; &, 154. 
The general physiognomy of this species is somewhat suggestive of Engraulis encrasicholus, 
the common anchovy of Europe, from which it may, however, he distinguished by characters 
expressed in the above diagnosis and referred to in the following description : 
The body is slender and compressed, narrower on the belly than on the back, although 
equally rounded off. The greatest depth is comprised nearly seven times in the total length 
and almost twice in the length of the head. The head constitutes the fourth of the total length. 
The eye is large and sub-circular : its diameter entering four times and a half in the length of 
the side of the head. The tip of the lower jaw hardly projects beyond the anterior rim of the orbit. 
The posterior extremity of the maxillar bone extends as far as the sub-opercle. The anterior 
margin of the dorsal fin is nearer the base of the caudal than the tip of the snout, and as high 
as its base is long. The anal is much longer than deep ; its base entering about seven 
times in the total length ; it is quite concave upon its middle and much deeper anteriorly than 
posteriorly. The caudal fin constitutes a little more than the sixth of the total length. The 
ventrals are inserted somewhat in advance of the dorsal fin, and, being quite small, their 
extremities do not extend as far as the vent; their posterior margin is broad when expanded 
and sub-convex. An elongated membranous scale exists near the outer margin of these fins, and 
another between them, similar to those of the pectoral fins. The pectorals themselves are 
much larger than the ventrals, broad when expanded, obliquely truncated posteriorly, almost 
linear. The axillar membranous scale is nearly as long as the upper edge of these fins. 
A vertical line dropped from the insertion of the last ray of the dorsal fin would intersect 
the vent, situated near the anterior margin of the anal fin. 
D 1, 14 + 1; A 1, 19 + 1 ; C 3, 1, 9, 8, 1, 2 ; V 8 ; P 17. 
The scales are very large, much deeper than long, undulating upon their anterior margin, 
and rounded off posteriorly, with a few irregular radiating grooves upon the anterior section. 
The upper surface of the head and the back are deep bluish brown or blackish ; the sides 
and inferior regions reflecting a uniform silvery tint. The dorsal and caudal fins are greyish 
yellow, whilst the anal, ventrals, and pectorals are of a light straw color. 
List of specimens. 
Catal. 
No. 
No. ol 
spec. 
Age. 
Locality. 
When col¬ 
lected. 
Whence obtained. 
Nature of speci¬ 
men. 
Collected by— 
941 
8 
Adult.... 
Shoalwater bay, W. T.. . 
1853 
Gov. I. I. Stevens . 
Alcoholic_ 
Dr. Jas. G. Cooper. 
942 
6 
-.-do. 
Astoria, Oregon.. 
1854 
Lieut. Tiowbridge. 
----do. 
Lieut. Trowbridge . 
943 
10 
1853 
_do_ 
_do. 
A. Cassidy_ 
044 
6 
1853 
Lieut. Trowbridge . 
945 
2 
1857 
A. Cassidy_ 
A. Cassidy_ 
