412 DR. GUNTHER ON THE FISHES OF CENTRAL AMERICA. 
‘The operculum terminates in three, flat, triangular teeth, the upper of which is the 
more distant and somewhat more obtuse than the others, the middle one being the 
longest, but not very prominent, and the lower one the shortest and weakest. ‘The 
suprascapula is concealed by the scales. 
Base of dorsal fin covered with very small scales, a tapering band of scales runs up 
between each pair of the spines and rays to about half the height of the fin. Spinous 
portion rather lower but longer than the soft, its upper margin convex ; the membrane 
between each spine is deeply notched, and there is a small membranaceous appendage 
behind the top of each spine. The first spine is the shortest, half the size of the 
second; the second is five-sixths of the length of the third; the third, fourth, and fifth 
are the longest, and of nearly equal length ; the spines then become gradually shorter 
to the last one, which is scarcely longer than the preceding. ‘The soft portion exhibits 
an entirely rounded upper margin, the rays becoming longer from the first to the sixth 
or seventh, and shorter from the fourteenth to the last; the first ray is one-fourth 
longer than the preceding spine. Caudal with the posterior margin convex. Anal 
commencing a little behind the commencement of the soft dorsal, and terminating in 
advance of the end of the same; the first spine is not very strong, and short; the 
second long, thick, and strong; the third more slender and shorter, being but little 
longer than the second dorsal spine; the margin of the fin is rounded throughout, the 
third ray being the longest, and the subsequent ones becoming progressively shorter. 
The pectoral is composed of eighteen rays, rounded, one-fourth longer than the ventral, 
and covered with minute scales for about one-third of its length. The ventral reaches 
to the vertical from the origin of the eighth spine of the dorsal, but not to the vent; 
the spine is a little less than two-thirds the length of the first ray ; the first and second 
rays are the longest, the others diminishing gradually in length; the length of the 
spine is somewhat less than that of the second dorsal spine. Canine teeth small in 
both jaws. 
This species varies somewhat in coloration, as most of its congeners; the spots are 
numerous aud small, either of a uniform dark-brown colour, or of a light colour and 
mixed with large brown spots. Pectoral fins with narrow blackish cross bands. 
One example, 10 inches long, and three smaller ones have been collected by Capt. 
Dow on the Pacific coast of Panama. ‘The latter have the spots somewhat larger and 
less conspicuous than the adult. This species cccurs also in the West Indies and at 
the Falkland Islands. 
15. RuyprTicUs DECORATUS. 
Rhypticus nigripinnis, Gill, Proc. Ac. Nat. Sc. Philad. 1861, p. 53. 
Promicropterus decoratus, Gill, . c. 1863, p. 164. 
D. ge) Ac 16; 
The two dorsal spines are continuous with the soft portion. Body generally with 
more or less numerous round whitish spots, many of which have a brown centre. 
