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. jS^iitHngii and of C. jnctiis Lowe. The disks lie trans- 

 versely in tlie canals, each upon a single flat elliptical or oblong scale, as in 

 Lampogi'ammus 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 e^e, 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 

 tlie base of the illicium 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 illicium 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. indvs, 

 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 sott 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 



