CHAUNAX COLORATUS. 85 
Scales rather separated, bases broad, convex and disk-like, cusps acicular, 
erect and prominent (Plate XVI, figs. 5-8). In most cases each scale has 
but a single cusp; on many there is more than one, notably along the 
lateral line and on the head, where there are two to eight spines on a single 
base; this polyspinous condition is a frequent result of coalescence of the 
bases of a number of distinct scales. Lateral system distinct, in distribution 
similar to that of C. Nudtingii and of C. pictus Lowe. The disks lie trans- 
versely in the canals, each upon a single flat elliptical or oblong scale, as in 
Lampogrammus and others, and as in that genus, each disk is spindle- 
shaped, pointed at each end, and has a rounded central body. The canals 
of the system are indicated by bare areas among the scales; one from the 
upper end of each maxillary passes back on the forehead, bending outward 
behind each eye, and thence going backward above the gill opening and 
turning down behind it the line extends along the lower half of the caudal 
region to the base of the caudal fin; another passes back from the 
symphysis below each mandible, united to its fellow by a line across the 
chin, and is continued above the pectoral; a third runs from each side of 
the base of the illicitum above each maxillary, going back along the side 
of each cheek, parallel to the mandibular branch, toward a branch from the 
aural region connecting the upper and the lowest line. A pair of spines 
on the cradle-like scale, one at each side of the channel, protects each 
disk, and between the tubercles immediately over the disk there are fleshy 
lobes and filaments. The channels do not present such a continuous 
appearance as is seen on C. Nuttingii, but appear more as if made up of 
a lot of isolated pieces of a channel. 
Behind the illicitum there is another rod lying upon the base of the first, 
and entirely hidden by the skin, and at the occiput there is another in 
similar condition (Plate XVI., fig. 1, and Plate XVII., figs. 2 and 4). 
The same conditions are found to obtain on C. Nuttingii and C. pictus, 
indicating the likelihood that these rudimentary concealed spines are generic 
characteristics. Fin rays protruding beyond the fin membranes. Second 
dorsal large, broadly curved in the upper outline, anterior ray short ; hind- 
most two rays bound together. Anal small, not quite reaching the base 
of the caudal, originating below the ninth ray of the soft dorsal; base 
ending below the end of that of the soft dorsal. Pectorals strong, rounded, 
low on the sides, carpal elements as long as the rayed portion (Plate XVI., 
fig. 1, Plate XVII., fig. 6), lower element longer than the upper and 
