14 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
and base of pectorals in male, anterior to it in female, the difference caused by enlargement of first 
two anal rays in male; anal fin small, rays slender, membranes of all deeply emarginated ; first two 
anal rays of male greatly enlarged, joined by membrane to each other and to rest of fin; posterior 
edge of tail nearly straight ; anal papilla inconspicuous. Cirri small and scarce, always occurring 
singly, never in bunches or joined at the base, except a few pairs along anterior third of lateral line, 
one above each orbit, two rows of three each behind these on top of head, one cirrus on inside of each 
uasal spine; a cirrus on end of maxillary, two or three on margin of preopercle below preopercular 
spine, and a row along anterior half of lateral line. 
Color, light olive or reddish brown tinged with lavender, marked dorsally with four or five 
° wedge-shaped indented spots of black, a broken band of same color along lateral line, sometimes 
sending branches below it, which show a tendency to inclose round spots; a more or less distinct 
spot of black on top of head; a faint postocular line, a spot below eye, and a preocular line running 
from eye to snout, all of same color; pectorals and caudal indistinctly barred with brown, anal 
tinged with it, and dorsal covered with fine brown or black spots, sometimes very faint; throat and 
belly pale yellowish- white, unspotted. 
This species is most closely related to Oxycottus embryum, with which it agrees in general colora- 
tion, but differs decidedly in the presence of scales, the slenderer body, the larger number of soft 
dorsal and anal rays, the serrated margin of the preopercle, and the arrangement of the cirri. 
Described from two specimens taken at Point Lobos, Monterey County, Cal., by A. W. Greeley. 
(Tyjte, No. 6067, L. S. Jr. Univ. Museum.) Eare ; only two other specimens from Point Lobos are known. 
It inhabits tide-pools lined with corallines, and in coloration imitates very closely these alg®. Length, 
40 mm. The smallest of our tide-pool fishes. 
Comparative measurements of two specimens of Kusdculus rimensis. 
Collectors and localities. 
Measurem en ts . 
Gredev, 
Greeley, 
Point, Lobos 
Point Lobos, 
(type), June, 1898. 
June, 1898. 
Extreme length, in millimeters — 
to 
39 
Greatest height of body 
20 
22 
Least height of caudal peduncle 
6 
7 
Length of caudal peduncle 
17 
16 
Length of head 
29 
28 
Width of head 
23 
23 
Width of interorbital space. 
7 
7 
Height atpupil 
15 
16 
Length of snout 
9 
9 
Diameter of orbit 
7 
7 
Distance from snout to spinous dorsal 
28 
28 
Length of spinous dorsal at base 
24 
27 
Greatest height of spinous dorsal 
10 
9 
Length of soft dorsal at base 
48 
47 
Height of longest ray of soft dorsal 
15 
15 
Distance from snout to anal 
43 
48 
Height of longest anal ray 
15 
14 
Length of caudal 
19 
19 
Distance from snout to pectoral 
30 
27 
Length of pectoral 
39 
38 
Distance from snout to ventral 
32 
32 
Length of ventral 
18 
18 
Number of dorsal spines - - . 
9 
9 
Number of dorsal rays 
17 
18 
Number of anal rays 
14 
14 
Number of pectoral ravs 
14 
14 
21 
DIALARCHUS Greeley, new genus. 
Preopercular spine forked at tip; scales none; first anal ray of male enlarged, joined to second, 
the two widely separated from rest of fin. Closely allied to Oliyocottus, differing only in character of 
anal rays of male. 
Dialarchus snyderi Greeley, new species. Fig. 4. 
Centridermichthys maculosus Gunther, Cat. Fishes, II, 171, 1860; not Oliyocottus maculosus Girard. 
Oliyocottus maculosus Jordan & Gilbert, Synopsis, 718, 1883; Jordan & Evermann, Fishes of North 
and Middle America, n, 2013, 1898. 
Oliyocottus snyderi Greeley, in Jordan & Evermann, Fishes North and Mid. Amer., in, 2871, 1898. 
