5. POLYACANXHUS. 



379 



3. Polyacanthus helfrichii. 



Sleeker, Borneo, viii. p. 162. 



D. li±9. A. ig-J- L-lat. 32. 



The height of the body is two-fifths of the total length (the caudal 

 fin not included), the length of the head two-sevenths. Lateral line 

 subinterrupted. Praeorbital not serrated. The first soft ray of. the 

 ventral fin is produced into two filaments. Coloration uniform. (Bl.) 



Rivers of Bandjermassing. 



4. Polyacanthus opercularis. 



Lahrus opercularis, L. Amoen. Acad. iv. p. 428 ; Bl. Schn. p. 245. 

 Chaetodon chinensis, Bl. taf. 218. fig. 1 ; Lacep. iv. pp. 461, 496 ; Bl. 



Schn. p. 2;M. 

 Polyacanthus chinensis, Cut. ^Fal. vii. p. 357; Richards. Ichth. Chin. 



p. 250. 

 Macropodus ocellatus. Cant. Ann. i^- 3faff. Nat. Hist. ix. 1842, p. 484. 

 Polyacanthus (?) opercularis, Ttichirds. I. c, 

 Polyacanthus (?) paludosus, Bichards. I. c. 



D. 1±±7 A. JI4" L. lat. 30. L. transv. 11-12. 



8-7 11-12 



The depth of the body is contained twice and a half or twice and 

 two-thirds in the total length (the caudal fin not included), the 

 length of the head three times. Lateral line none. A round black 

 spot on the extremity of the operculum. 



China. Chusan. 



Var. a. Body and tail uniformly coloured, or with an oblong 

 blackish spot above the anal fin. The soft portions of the vertical 

 fins dotted with greyish (in spirits). 



a-b, c. Fine specimens. Hongkong. Presented by Sir J. Bo wring. 

 d, e. Adult. Chusan. Presented by the East India Company. — 

 Types of M. ocellatiis, Cant. 



Var. j3. Reddish, with irregular silvery transverse streaks. 

 f-7i. Fine specimens. Hongkong. Presented by Sir J. Bowring. 



Var. y. Greyish or reddish, with brown transverse bands. 

 i. Many specimens. China. 



There cannot be the slightest doubt that a specimen of this species 

 has served for the wretched sketch to which Sir J. Richardson has 

 given the denomination of P. poludosus. The typical specimen 

 was evidently in a bad state of preservation, and the artist has 

 been more careful in representing the marldngs of the fish than the 

 fin-rays, &c. 



5. Polyacanthus signatus. 

 B. 6. D. ^^ A. '^. L. lat. 29. L. transv. 4/9. Vert. 10/16. 

 The height of the body is contained twice and a half in the total 



