1849.] Catalogue of Malayan Fishes. 1419 



acute. The ventrals are tetragonal, considerably projecting beyond 

 the pectorals. The dorsal commences at the termination of the 

 ventrals, and extends a little beyond their apex. The tail is about 

 3 to 3 \ times the length of the body ; the anterior third is greatly 

 compressed ; the rest flagelliform. At a short distance from the dorsal 

 is situated a small spine, but little longer than the base of the dorsal ; 

 a little behind it appears a second, scarcely longer than the preceding 

 spine. In the young the back is smooth. In older individuals M. M. 

 Miiller und Henle describe the back as being rough from minute spines 

 with stellate base. At Pinang this species occurs at irregular intervals, 

 singly or a few together. The following dimensions were taken from a 

 young female. 



From the incision of the snout to the centre between the 



nostrils, 1 inch. 



„ the nostrils to the mouth, Of 



„ the mouth to the anus, 5f 



Length of the tail, 24 



Breadth of the margin of the nasal valve, 14 



„ of the mouth, 1 \ 



„ of the disk, 13 



Length of the posterior margin of the pectorals, Of 



„ of external margin of the ventrals, If 



„ of each caudal spine, Of 



FAM. DICEROBATIDIDiE. 



Gen. Dicerobatis, (Diarobatus, Block,) Blainville, 1828. 



(Cephalopterus,* [DumSril,'] Risso, 1810. — Cephaloptera, Risso, 



1826.) 



Mouth on the abdominal surface. Teeth of both jaws minute, flat- 

 tened, like paving stones, of different forms. The rays of the pectorals 

 extend closely to the skull. The anterior margin of the pectorals is 

 convex from the skull behind the eyes to the apex.f 



* Pre-occupied by Cephalopterus, Geoffroy, 1809, (Aves.J 

 f Cephaloptera, Miiller und Henle, page 184. 



