40 
U. S. S R. K. EXP. AND SURVEYS-ZOOLOGY-GENERAL REPORT. 
List of specimens. 
Catalogue number. 
No. of specimens. 
Locality. 
Whence obtained. 
Nature of specimens. 
Collected by— 
286 
1 
Lieut. Towbridge__ 
Alcoholic_ 
A. Cassidy_ 
Tribe of Cataphracti, or mailed cheeks. 
A feature common to ail the “ mailed cheeks ” consists in the extension backwards of one, 
and sometimes two, of the sub-orbital hones as far as the limb of the preopercle, thus con¬ 
stituting a bridge, or else a bony buttress across the cheeks. 
We begin the series with the Heterolepid family, which, by its general aspect, reminds us of 
the Trachinids of the percoid tribe, thus bringing the two groups in closer union. 
The family of Triglidce, of exclusively marine habits, and which is composed of the gurnards, 
sea-robins, and sea-swallows of the Atlantic coast, has furnished no representatives along the 
Pacific coast. 
The cottoids, or sculpins, and hull-heads, on the other hand, seem to compensate for the 
absence of the former in the fresh waters of the western slope of the Rocky mountains, and 
especially in the sea. 
The scorpaenids, or sea scorpions, and rose fishes, exclusively marine also, are well represented, 
particularly in species of the rose-fish genus, or Norway haddock. 
The gasterosteid, or sticklebacks, of the fresh and brackish waters are likewise quite 
numerous. 
Family IIETEllOLEPIDAE, Girard. 
The natural characters which may he assigned to this family, in order to distinguish it from 
the other groups of Cataphracti, or mailed cheeks, consist in an elongated, sub-fusiform, and 
rather compressed body, covered with small scales, varying in size, shape, and structure, being 
either ctenoid or cycloid. The dorsal region is almost entirely occupied by a long and continuous 
fin, or two distinct fins, more or less contiguous, composed of undivided rays in the former case, 
of undivided and of articulated ones in the second. The anal fin is elongated, and, generally 
speaking, resembles the soft portion of the dorsal, with the exception that the interradial 
membrane is more or less emarginated. The ventral fins are situated under the pectorals. 
Canine teeth exist upon the jaws ; either canine, or velvet-like ones, or both kinds upon the 
vomer and palatines. The head above is spineless, provided sometimes with membranous flaps, 
like Scorpaena. The opercle and preopercle are either smooth or provided with small spines. 
A bony arcade, formed by the sub-orbitals, may he traced across the cheek, concealed under the 
flesh, skin, and scales of that region, and which tells of the affinities of this family with the 
tribe of Cataphracti. 
