io6 

 MELANONOSOMA, n.g. 



Head quadrilateral, body compressed, especially towards 

 caudal region, which terminates in a long tapering tail. 

 Mouth wide, anterior and lateral. Both jaws with narrow 

 bands of villiform teeth ; teeth on vomer and palatines. No 

 barbel. One long undivided dorsal fin commencing over the 

 pectorals and ending a short distance in front of the caudal 

 rays. One anal, commencing about the middle of the body, 

 similar to the dorsal, not confluent with caudal rays, though 

 separated from them by a short space. Pectorals and 

 ventrals narrow, in the same vertical line. No pseudo- 

 branchiae. 



Very near to the genus Mekuwnus Giinther, but has not 

 the anterior division of the dorsal described by him. The 

 " posterior division ' of the dorsal and anal are present as in 

 his description of Melanonus, but as these are here regarded 

 as part of the caudal the present genus is described as having 

 one dorsal and one anal. 



MELANONOSOMA ACUTECAUDATUM, n.sp. 



Br. 7. D. 66. A. 49. V. 5. 



Length of head nearly 6i in length of body. Depth of 

 head and body nearly equal, contained i\ times in length of 

 body. Diameter of eye 4 times in length of head. The dorsal 

 commences at a point in the vertical from the pectoral and 

 ventral, and consists of feeble rays bound together by a very 

 delicate membrane, the longest occurs in the anterior part, 

 and is a little more than half the length of the head. The 

 anal commences immediately behind the anus and under the 

 2 1 St ray of the dorsal. It is similar to the dorsal though 

 more delicate, and its longest rays are only about half the 

 length of those of the dorsal. The posterior rays of both 

 dorsal and anal overlap the small caudal rays, reaching to 

 about the 3rd or 4th when laid along the body. There are 

 about 50 rays in the caudal, four of the posterior median are 

 prolonged, lieing longer than the longest dorsal by about a \ 

 of its length. The caudal region bears a very close resem- 

 blance to that of Melanonus. A series of 5 scales between 

 the dorsal and lateral line and 9 between lateral line and 

 ventral median line. A large mucous pore immediately 

 above the eye and many smaller ones scattered over the 



