1849.] Catalogue of Malayan Fishes. 1209 



fins have their basal third covered with scales. Immediately above 

 the latter scales, on both sides of the fins, in the centre between each 

 pair of rays, appears a very distinct rounded aperture, the margin of 

 which is a little raised, and the bottom of which is formed by a lamina 

 of the fin membrane. From the upper part of each aperture proceeds a 

 linear fold, which may be traced to the external margin of the fins. 

 Commerson discovered a similar row of pores along the base of the 

 dorsal and anal rays of Achirus marmoratus, Lacepede ;* and later, Dr. 

 Riippell observed similar in Achirus barbatus, Geoffroy.f The caudal 

 is scaly, rounded, f of the length of the head. The right ventral is 

 broad, rounded ; all the rays are divided, f of the length of the head ; 

 the fifth ray is throughout connected by a membrane to the first anal. 

 The left ventral commences a little more backward ; it is narrower and 

 shorter, and not joined to the anal. A single individual was observed 

 at Pinang in August 1843. 



Gen. Plagusia, Brown, 1755. 

 Dorsal, caudal and anal fins united ; otherwise resembling Achirus. 

 Eyes and colour on the left side. 



Plagusia bilineata, (Bloch.) 



Pleuronectes bilineatus, Bloch, PI. 188. 



Pleuronectes bilineatus, Linne : Syst. 1235. 



Russell, LXXIV. Jerree Potoo E. 



Pleuronectes bilineatus, Shaw, IV. 317. 



Plagusia bilineata, Cuv. R. A. Ed., 224. ( 8 ). 



Plagusia bilineata, Riippell, Atlas, 123. 



Plagusia dipterygia, Riippell, ibid. 123, Taf. 31, Fig. 3, (Young.) 



Pleuronectes bilineatus, Bennett : Life of Raffles, 692. 



Plagusia bilineata, Riippell : Neue Wirb. Fis>che, 84. 



Plagusia dipterygia, Riippell, ibid. 



Plagusia bilineata, Swainson, II. 303. 



Plagusia bilineata, Bleeker : Verh. Batav. Gen. XXII. 5. 



Ikan ledah of the Malays. 



* Lacepede, IV. 660.— Pleuronectes marmoratus, Shaw, IV. 310. 

 t Ann. du Mus, I, PI. XI.— Riippell : Atlas, 122, Tab. 31, Fig. 2. 



7 Q 2 



