504 TELEOSTET. ACANTnorTEttYGII. 



667. (2.) Dules argenteus. 



Perca argentea, Bennett, Fish. Ceylon, p. 22, pi. 22. 



Dules argeuteus, Day, Fish. India, p. 67, pi. xviii, fig. 2 (see synon.). 



D. 10/9-10. P. 15. A. 3/10-11. C. 17. L. 1.52. L.tr. 6/12. 



Length of head nearly 4, height of body 3| in the total length. Eyes 

 diameter 2,^ in length of: head, | from end of snout, and f apart. 

 Fins dorsal spines not very strong, fifth and sixth the highest ; 

 second anal spine slightly shorter but stronger than third ; caudal 

 forked. Colour bluish, becoming silvery white on the sides and 

 abdomen ; soft dorsal greyish black along its upper third and with 

 a white outer margin ; caudal milk-white, with two oblique yel- 

 lowish-black bands on each lobe and a narrow central black longi- 

 tudinal one. 



A young specimen 1 inches long is blue with two narrow black 

 lines on each sichj, one at the base of the dorsal fin, the other a 

 little below ; anal and dorsal black-tipped. 



Hob. East coast of Africa, seas of India, the Malay Archipelago 

 and beyond ; attaining 6 inches or more in length. 



Sixth group. THERAPONINA. 

 14. Genus THEKAPON, Cuv. 



Syn. Pelatcs, sp., Cuv. ; Datnia, Cuv. & Val. 



Branchiostegals six ; pseudobranchiro. Eyes of moderate size. 

 Opercle with spines. Preopercle, and sometimes preorbital, ser- 

 rated. Teeth villiform in both jaws, the outer row sometimes the 

 larger; deciduous teeth on the vomer and palatines. Dorsal fin 

 single, but more or less notched, having from 11 to 13 spines; anal 

 with three. Scales of moderate or small size. Air-bladder divided 

 by a constriction. Pyloric appendages few or in moderate numbers. 



Geographical Distribution. Eed Sea, east coast of Africa, seas of 

 India, Malay Archipelago, and Australia. These fishes in India 

 are marine, but some are occasionally found in brackish water 

 within tidal influence ; they may even live temporarily in brackish 

 or even freshwater ponds. 



Uses. Species of this genus are not esteemed as food, as they are 

 reputed to feed on carrion, but they are eaten by the poorest class 

 of natives. 



The colour of these fish is usually silvery, with longitudinal 

 bands ; but in some species cross bands are present in the im- 

 mature. 



Synopsis of Indian Species. 



A. Dark oblique bands on caudal fin. 



L. 1. 90-100. Lateral bands straight, no 



mark on anal 1. T. pitta, p. 505. 



L. 1. 80-90. Lateral bands curved .... 2. T. jarlva, p. 505. 

 L. 1. 50-55. Lateral bands straight, a 



black mark ou anal 3. T. thcraps, p. 500. 



