138 
KtTROPEAN HALFBEAK. 
it differs from those of the Garfish, which are proportionally 
shorter, wider, and not pointed; the fin-rays nine. Dorsal and 
anal fins far behind and opposite, reaching to the origin of the 
tail; hut in the examples received from Mr. Martin, the anal 
was a little in advance of the dorsal ; rays in the former nineteen, 
in the anal twenty-two. Tail concave. In Mr. Martin’s fishes 
the upper jaw was arched or humped where it joined the head, 
which was not the case with other examples. The elevated 
line of scales which passes along the border of the belly on each 
side in the Garfish is not visible, even with the aid of a lens, 
in this Halfbeak. 
The special use of the remarkable formation of the jaws in 
this fish can only be guessed at; but the observations of Mr. 
Swainson seem to he appropriate: — “It is a remarkable circum- 
stance that we have a genus of birds equally unique in its 
own class, where the mouth is similarly constructed; inRhyncops, 
or Skimming Terns, the upper jaw in fact is considerably shorter 
than the lower; and these birds skim along the surface of 
the sea to feed upon those minute animals which are only to 
he found there. This well- authenticated fact throws considerable 
light upon the probable habits of these fishes,” which we are 
led to believe, “habitually feed much in the same manner.” It 
was particularly noticed in the little example while alive that 
the upper jaw only was seen to move. 
