190 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
has kept distinct from the parent sjieeies while migrating from one lake to the other through 
salt water. The name microcephalus therefore Becomes a mere couvenieuce, and does not 
represent a true variety. 
The form known as williamsoni is limited in its distribution, and, so far as is now known, 
represents a true variety. To put these forms in their true relation the name microce 2 >halun 
would have to be abandoned and the forms represented by it considered as transitional 
between the species catap/hractas and the variety williamsoni. 
3. Cottus aleuticus Gilbert. 
Found in Karluk River and Lake and in Alitak Lake. Common. The following table 
shows the measurements of eleven specimens from the two lakes, the head and dojith being 
expressed in hundredths of the body. Length of specimens from 1.8 inches to 2.7 inches, the 
caudal tin not included. 
Head. 
Depth. 
Dorsal. 
Anal. 
No. of 
Proportion 
No. of 
Proportion 
No. of 
No. of 
No. of 
No. of 
specimens. 
of body. 
specimens. 
of body. 
specimens. 
rays. 
specimens. 
rays. 
1 
0. 29 
1 
0. 19 
10 
IX-19 
]2 
6 
0. 30 
4 
0. 20 
1 
IX-20 
6 
13 
2 
0. 31 
5 
0.21 
4 
14 
2 
0. 32 
0. 23 
4. Myoxocephalus polyacanthocephalus (Pallas). 
Common at Karluk; often taken in the seine when fishing for salmon, but not often found 
in the rock pools. The following are measurements of two specimens, the head aud dejith 
being exiiressed in hundredths of the body : 
Specimen 
2 inches long. 
Specimen 
13 inches long. 
Head 
0.44 
0.4C 
Depth 
0. 27 
0. 22 
Dorsal 
X-15 
X-14 
Anal 
13 
12 
5. Leptocottus armatus Girard. Not very common. Only two specimens found at Karluk. 
6. Oligocottus maculosus Girard. 
Uligocottus iorealis Jordan & Snyder, Proc. Cal. Ac. Sci. 1896, 225, Neah Bay, Washington. 
Common at Karluk. 
SIGMISTES Rutter. 
Sigmistes Rutter, in Jordan & Evermann, Fishes of North and Middle America, part iii, 2863, 1898 
{caulias). 
This genus differs from Oxycottus, to which it is most closely related, in the deep, compressed 
body, strongly arched lateral line, long dorsal fin, and largo mouth; body deep aud com- 
pressed; skin smooth; lateral line strongly arched anteriorly; gill membranes united, free 
from isthmus; no slit behind last gill; preopercular spine simple, short, strongly curved 
upward; anal papilla large; vent immediately behind ventral fins, about three-fifths of dis- 
tance from gill membrane to anal tin; veutrals, 1, 3. 
(6iyjna, the letter s, from the form of the lateral line.) 
7. Sigmistes caulias Rutter. 
Sigmistes caulias Rutter, in Jordan & Evermann, Fishes of North and Middle America, part in . 
2863, 1898, Karluk, Alaska- 
Head 3.4 ; depth 3.5; D. ix, 20 (ix, 21 in one specimen) ; A. 15 (14 in two specimens) ; P. 13, 
Back elevated, body compressed; eyes lateral, 4.34 in head; snout 3.50; cleft of mouth lateral; 
maxillary 2 in head, reaching to below pupil (only a little past front of eye in one specimen) ; 
teeth coarse, cardiform, the inner row of upper jaw enlarged, almost eanine-like; a pair of 
similar teeth near symphysis of lower jaw; a small patch on vomer, one on front of palatines; 
preopercular spine small, sharp, appressed, strongly curved upward, the preopercular maVgiu 
without spines or tubercles below it; nostrils in tubes, one pair directly behind nasal spines, 
the other lateral, directly in front of eyes; nasal spines strong, sharp; a pair of tufted cirri 
above eyes, a pair simple or branched at occiput, and a pair of simjile cirri halfway between 
