140 
U. S. P. R. E. EXP. AND SURVEYS—ZOOLOGY—GENERAL REPORT. 
lateral myocomma. This groove is, moreover, furnished with a thin though opaque membrane, 
which gives it the appearance of a ridge, especially along the abdominal region, where it is 
more developed than further behind. 
The dorsal region is greyish brown ; the lower half of the sides and the belly being silvery; 
the base of the caudal is black. 
List of specimens , 
Catal. 
No. 
No. of 
spec. 
Sex and 
age. 
Locality. 
When 
collected. 
Whence obtained. 
Nature of 
specimens. 
Collected by— 
612 
3 
Adult.. 
Cape Flattery, W. T_ 
1855 
Lieut. W. P. Trowbridge. 
Alcoholic. 
Lieut. Trowbridge_ 
SUB-ORDER II. 
THORACIC!. 
The ventral fins being present, they are inserted under the thoracic belt, beneath the pecto¬ 
rals, or somewhat in advance of the latter. 
Three families compose this sub-order, two of which have furnished us with representatives 
from the Pacific coast. The third, or that of Echeneidae , is, so far, unknown in that region. 
Syn. — Thoracici, Linn. Syst. Nat. ed. X, 1758, 260.—Iconogr. Encycl. II, 1850, 204. 
Fishes with a thoracic position of the ventral fins are met with in some of the other orders 
of the class, but that character is more subordinate yet, having not the value it is entitled to 
amongst anacanthinians. 
Family GADIEAE^ Bonap. 
When told that the codfish typifies this family it is enough to enlist the attention of our 
readers. The cod-fisheries, and the immense trade connected with them, is one of the greatest 
sources of wealth to a sea-coast population. 
Most of the representatives of this family, cod, haddock, frost fish, hake, coal fish, &c., are 
tenants of the frigid and temperate waters, and generally of marine habits; the ling or methy, 
and allied species, being the only ones found in fresh waters. 
Their body is elongated, sub-fusiform in profile, either covered with small or moderate scales, 
cycloid in structure, often hidden in the thickness of a soft skin. The head is proportionally 
well developed; the mouth large or moderate. Its upper surface generally scaleless; sometimes 
the cranial region is covered with minute scales. The teeth are varying between the rasp or 
card-like type and the slender canines; they are acerated, unequal in size, disposed upon 
irregular series on both jaws, and the front of the vomer ; the palatine, bones being toothless. 
The premaxillar bones constitute almost exclusively the upper arcade of the mouth and bear 
the teeth at the exclusion of the maxillaries, which appear towards the angle of the mouth 
only. The opercular apparatus is spineless. The gill apertures are wide, extending obliquely 
forwards under the head, where they are continuous ; the branchial rays being six or seven in 
number on either side. 
