412 DB. GUNTHBE ON THE TISHES 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 fii'st 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 sjiine is a little less than two-thirds the length of the first ray ; the fii-st and second 

 rays are the longest, the others diminisliing 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 and 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. RHYPTICUS DECOEATUS. 



Rkypticus nigripinnis, Gill, Proc. Ac. Nat. Sc. Philad. 1861, p. 5.3. 

 Promicropterus decoratus, Gill, /. c. 1863, p. 164. 



D. I,. A. 16. 



Tlie 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. 



