388 Prof. Agassiz on Viviparous Fishes from California. 
Jess and less in the others. Still within the row nearest the eye, 
there is a space without scales, aud marked by pores radiating from 
the edge of the orbit. The posterior and inferior border of the 
preopercle, outside of the ridge of the latter, is thin, membranous, 
and without scales, but marked with numerous pores or tubes 
similar to those around the orbits, and radiating from within out- 
wards. 
The opercle, subopercle, and interopercle are covered with 
scales, which decrease in size from the former to the latter. There 
is a narrow membranous border to the opercle, extending from its 
posterior angle to the height of the termination of the lateral line. 
The notch between the subopercle and interopercle is on a vertical 
line with the edge of the posterior border of the preopercle. There 
is a small patch of scales, nine or ten in number, immediately 
above the superior attachment of the preopercle. ‘The dorsal fin 
extends over about ths of the superior curve of the body ; its pos- 
point of each spine, the fin appears to extend backwards in a loose 
filament. There are 192 articulated rays in the dorsal fin: the 
superior outline of this part is nearly similar to that of the back, 
although the rays of its first halfare the longest, and nearly equal 
in length. The furrow on each side extends as far forwards as 
the base of the first articulated ray, where there are three rows of 
scales forming the sheath ; but the rows are reduced to one to- 
wards the posterior attachment of the fin. 
The pectoral fins are of rather large size, and are placed below 
the middle line of the body, as well as below the posterior angle 
of the opercle, They extend about as near to the anal fin, as do 
the ventrals. ‘The second ray of the pectoral is but slightly arched 
towards its extremity. There are twenty-one rays in each pectoral. 
The base of the ventrals is just in advance of the middle of this 
second ray of the pectoral. The spinous ray of the ventrals is $ths 
the length of the following articulated ray. There is a long plate 
of scales between the ventrals. The anal fin is broad and com- 
posed principally of fine slender rays. The last and longest of 
of the tail. The candal fin is deeply forked; it contains fourteen 
rays, omitting its outer and short rays. ‘There are eight rows of 
scales between the lateral line and the spinous portion of the 
dorsal fin, and eighteen rows below the lateral line in the same 
region. Sixty scales in the lateral line. Color uniformly dark 
live brown, along the back, fading slightly upon the sides; dor- 
