OPAH. 197 



The number of fin-rays arc 



D. 2 + 52 : P. 28 : V. 1 -f 9 : A. 1 + 25 : C. 30. 



The length of the body including the tail is to the depth 

 of the body without the fins as two to one ; the form of the 

 body oval ; the profile of the head, both above and below, 

 fulling in with the outline of the body ; the mouth small, 

 without teeth ; tongue thick, with rough papillae pointing 

 backwards, and well calculated to assist in conveying food 

 towards the pharynx. The base of the dorsal fin is rather 

 longer than the depth of the body, the first eight or nine rays 

 elongated, the longest four times as long as the rays of the 

 posterior portion ; pectoral and ventral fins very long, full 

 one-third the whole length of the body and tail ; the anal fin, 

 which is preceded by a triangular scale pointing backwards, 

 equal in length to half the length of the base of the dorsal ; 

 the tail in shape lunate. The ventral, pectoral, and anterior 

 part of the dorsal fins falciform ; the lateral line forms an 

 elevated arch over the pectoral fin, its highest part being im- 

 mediately under the longest ray of the dorsal fin. 



The upper part of the back and sides are of a rich green, 

 reflecting both purple and gold in different lights, passing 

 into yellowish green below ; above and beneath the lateral 

 line are various round yellowish white spots, from which the 

 fish received the name of Luna ; the irides are scarlet ; all the 

 fins bright vermilion. 



The showy colours with which the Opah is ornamented 

 induced an observer to remark, that it looked like one of 

 Neptune's lords dressed for a court-day. 



