418 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 
58. Cottus aleuticus sp. noy. 
Uranidea microstoma, Lockington, Proc. U. 8. Nat. Mus. 1880,58; not of Heckel. 
In appearance resembling C. philonips ; the head small, its width but one-fourth 
greater than its depth, the body low and but little compressed, the depth at shoulders 
but little greater than the width. Caudal peduncle moderate, not slender, its length 
from base of last anal ray 13 to 1+ in head; measured from last dorsal ray but little 
more than half as long. Depth of caudal peduncle 4} to 44 in head. 
Head small, 3} to 34 in length; depth 5 to5. Mouth small, variable, maxillary 
reaching vertical from front or middle of pupil, 23 to 3 in head. Vomerine patch of 
teeth small, the palatines toothless. Preorbital as wide as eye, produced anteriorly 
into a convex lobe which conceals all but the widened tip of the maxillary. Both 
pairs of nostrils opening in short but evident tubes, a character not known by us to 
exist in any other species of the genus. Eye 44 to 4? in head. Interorbital space 
narrow, the least width of the bone slightly less than half the vertical diameter of 
orbit, in adults 160 mm. long, much narrower in younger specimens. In this respect 
our specimens differ conspicuously from the types of C. microstomus, in which the 
interorbital width is said to equal vertical diameter of eye. As in C. philonips, we 
have but a single preopercular spine, which is straight and directed obliquely upward. 
Preopercular margin below the spine evenly rounded. Subopercular spine well 
developed. 
Lateral line complete, following outline of back to opposite last dorsal ray, where 
it abruptly declines to middle of caudal peduncle. Body naked or with a narrow 
band of prickles extending from upper axil of pectorals along under side of lateral 
line. 
Dorsals more or less joined at base in all our specimens, but varying in the height 
of the connecting membrane, which usually joins well up on first ray of soft dorsal, 
sometimes at its extreme base. The spinous dorsal is long, with 9 spines in 18 speci- 
mens examined, 10 spines in 5 specimens. The first two spines are very closely 
approximated, and spring from a single wide interspinal. The first spine is easily 
overlooked, as has been done by us (Investigations in the Columbia River Basin, 
1894, p. 54), and possibly also by Lockington in his description of C. micros- 
tomus. Spinous dorsal low, the soft dorsal higher, the longest rays equaling length 
of snout and half eye, the last rays when depressed not quite reaching base of 
caudal. Anal fin much shorter than soft dorsal, its last ray under the fourth or fifth 
before the last ray of dorsal. Caudal truncate, slightly rounded when spread, its 
length 14 to 13 in head, its rays twice forked. Pectorals reaching to or nearly to 
front of anal. Ventrals varying in length, not quite reaching vent in any of our 
specimens. Pectoral rays all simple. Dorsal and anal rays all simple except the 
last, which is usually divided to the base in the dorsal, and sometimes divided in 
the anal. 
Dorsal 1X or X,18 0r 19; anal 13 or 14; pectoral 13 to 15; ventral 1,4; caudal 8 or 9 
(forked rays); 35 to 37 pores in lateral line. 
Head and body light brown, mottled or spotted above, the darker markings on 
back often arranged as six crossbars, of which two are below spinous dorsal, three 
below soft dorsal, and one on caudal peduncle. These are usually broken up into 
spots or reticulations, and are often obscure, sometimes wanting. Usually a light 
bar downward and backward from eye. Rays of dorsals, pectorals, and caudal 
crossed with series of dark blotches. Ventrals and anal light, very obscurely barred — 
with darker. 
This species was very abundant in the small stream passing through the village 
of Iliuliuk, Unalaska, living both in the upper strictly fresh-water portion of the 
stream and in the lower more or less brackish part. A specimen transferred to the 
salt-water aquarium on the Albatross seemed to suffer no inconvenience from the 
change of water and lived for several days. This is probably the Uranidea micros- 
toma of Lockington, based on specimens collected near St. Paul, Kadiak, and con- 
