95 



* 



Length over 360 mm. [Specimen of Bleeker's collection in the 

 Leyden Museum examined]. 



Habitat: Java (Krawang !) ; Borneo (Sambas, Pamangkat 

 Sarawak). 



In rivers and brackish water. 



5. Ophisthopterus Gill. 



(GiLL. Proc. Acad. Nat. Sc. Philadelphia 1861, p. 31). 



(Pristigaster Gthr. p. p. ! ). 



Oblong, strongly compressed, ventral profile strongly serrated, 

 especially convex between chin and pectorals. Lower jaw pro- 

 jecting, maxillary vertical, rounded behind, reaching farther 

 than its supplemental bone but not produced. Small teeth on 

 jaws, palatines, pterygoids and tongue, none on vomer. Dorsal 

 fin short, inserted far behind origin of anal. Anal long with 

 more than 50 rays. Ventrals wanting. Caudal deeply forked. 

 Scales moderate, thin, deciduous. Gillrakers 28 30, stout, 

 much longer than branchial filaments. 



Synopsis of the species. 



A. Maxillary twice in head, supplementary bone rea- 

 ching as far as maxillary (see fig. 31). Pectorals 



shorter than head 0. tartoor p. 95. 



B, Maxillary ii/a 1 4 / 8 in head, excluding the supple- 

 mentary bone totally from the caudal border of 

 the upper jaw (see fig. 32). Pectorals longer than 



head 0. macrognathus p. 96. 



i. Opisthopterus tartoor (C. V.) 



Fig. 31. Opisthopterus tartoor (C. V.) 

 i Intermaxillary, m maxillary, / ligament between them, s s' supplemental bones. 



i) See Max Weber & L. F. de Beaufort, Verhand. Akademie Amsterdam 

 XVII, N. 3, 1912, p. 9. 



