353 



cleft small, oblique; maxillary extending beyond middle of eye, 

 to its frontborder or usually not so far. Mandibles prominent. 

 Praeorbital entire. Jaws with a band of small, fixed, conical 

 teeth ; none on palate. Scales ciliate, large, regularly arranged. 

 Lateral line an interrupted series of small pores in the centre 

 of the scales. Dorsal short, acute or rounded, with or without 

 a single spine and with 7 10 rays, some of which may be 

 strongly produced ; inserted far behind middle of length (without 

 caudal). Anal long, with or without i 4 spines and with 

 20 32 soft rays, which are usually not branched or only 

 posteriorly, where they may be produced. Caudal rounded or 

 pointed, its central rays often produced. Pectorals more or 



Fig. 92. Betta anabatoides Blkr. n.s. 

 The figure does not show the dark lines along the transverse series of scales. 



less pointed. Ventrals inserted below or in advance of pectorals, 

 with an usually weak spine and five rays, the outermost of 

 which is more or less prolonged. Opercular bones entire. 



Distribution: Islands of the Archipelago from Sumatra 

 to Java and Borneo, Malay Peninsula and Siam. 



In rivers, brooks, ponds and lakes. 



Note. The species of this genus are difficult to distinguish 

 even after the valuable revision of it by TATE REGAN, which 

 was the first attempt to bring order in the former chaotic 

 state of species. Most of them show a confusing variability of 

 characters according to size, sex and locality and seem partly 

 not yet to be fixed. The following key to distinguish them is 

 therefore not very satisfactory. 



Key to the indo-australian species of Betta. 



I. All the rays of dorsal and anal articulated. 



a. Maxillary extending beyond middle of eye . . . . B. macrostoma p. 355. 



b. Maxillary not extending beyond frontborder of eye. B. unimaculata p. 355. 

 INDOAUSTRALIAN FISHES IV. 23 



