22 



Body long, slender, and highly compressed. Head of moderate 

 size, pointed ; snout acute ; lower jaw rather longer than upper ; 

 maxillary narrow, its posterior border for the greater part of its 

 length slipping beneath the thin preorbital. Eye fairly small, 

 situated well forward of the centre of the head. Interorbital 

 space high, smooth, and convex ; preopercle smooth; opercle finely 

 ciliated. Maxilla reaching to below first third of eye. 



Teeth small and conical, forming single series in both jaws. 

 Long narrow patches on the palatines and a small patch on the 

 head of the vomer. Tongue without teeth. 



Fins : Spinous dorsal originating a little behind insertion of 

 pectoral ; spines long, weak and flexible, folding in a groove, 

 longest spine, 2-10-2-25 in the length of the head and about equal 

 to the length of the postorbital portion of the head ; second dorsal 

 short, its anterior rays elevated, the longest 2-90-3-05 in the 

 length of the head, last two rays almost separated into finlets. 

 Last two dorsal finlets connected by a very thin membrane. 

 Distance between base of last dorsal finlet and base of caudal lobe 

 4*25-4-55 in the length of the head. Origin of anal beneath about 

 the middle of the second dorsal ; fin similar to, though lower than, 

 the second dorsal ; its longest ray 3-85-4-05 in the length of the 

 head. Last two anal finlets connected by a very thin membrane. 

 Caudal very deeply forked. Pectoral short, scarcely falcate, its 

 length contained 1-75-1 '80 in the length of the head. Ventrals 

 exceedingly large,* broad, and may be laid back and completely 

 concealed in a deep fissure on the abdomen. This fissure ext nds 

 from the base of the ventrals to the anus, and in its deepest part 

 is almost equal to the diameter of the eye. The ventral is about 

 two and a half times as long as the pectoral, and is contained 

 2 80-2-85 in the length of the head. 



Scales deciduous, of moderate size, thin and cycloid ; concen- 

 trically striated. Upper part of head from above eyes forward 



* The possession of these relatively enormous ventral fins would 

 appear at first sight to be altogether out of keeping with a iUh which is 

 quite obviously pelagic in habit and a rapid swimmer ; but when the 

 highly-compressed form and somewhat wedge-shaped abdomen are con- 

 sidered, it is seen that if the fish were moving slowly it could hardly retain 

 its balance in the water without the aid of some such organs. Particularly 

 must they be of use if, as is probable, this species subsists to some extent 

 upon slow-moving pelagic organisms. Of course, in rapid swimming, the 

 ventral fins would be laid back in their groove. 



