224 L. Agassiz on 
tubes similar to those around the orbits, and radiating from 
within outwards. 
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, ex- 
tending from its posterior angle to the height of the termin- 
ation 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 ex- 
tends over about 2ths of the superior curve of the body ; its 
posterior portion is one-third higher, as well as longer, than 
its anterior. The spinous portion has nine or ten rays, the 
length of the first of which is equal to one-third that of the 
last. At the point of each spine the fin appears to extend 
backwards in a loose filament. There are 194 articulated 
rays in the dorsal fin: the superior outline of this part is 
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 towards 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 pos- 
terior 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 ven- 
trals are just in advance of the middle of this second ray of 
the pectoral. The spinous ray of the ventrals is 3ths the 
length of the following articulated ray. There is a long 
plate of scales between the ventrals. The anal fin is broad, 
and composed principally of fine slender rays. The last 
and longest of its spinous rays equals in length th that of 
the following articulated ray, which latter is equal to the 
corresponding ray of the dorsal fin. The last ray of the 
anal fin is placed nearer the caudle fin than that of the dorsal, 
