high in smaller specimens. Colour of alcohol specimens brownish 

 above, lighter and more or less silvery below, the two colours 

 separated by a longitudinal black band, which has the breadth 

 of about two scales and runs from behind eye to middle of 

 base of caudal; it is generally broader and more distinct in 

 its posterior part. Above the anal a more or less distinct 

 second band, parallel to the first and sometimes only indicated 

 by a black patch or totally absent. Fins more or less dusky, 

 base of second dorsal and anal generally darker. Length 135 mm. 

 Habitat: New Guinea (rivers Timena !, Sekanto !, Begowri !, 

 Sermowai!, river near Njao!, river Wagami !, river Mimika, 

 Strickland and Goldie river, Sageri); Aru-Islands!. 



Note. Specimens from the Aru-Islands (R. senckenbergianus) 

 seem to be a little more elongate. Height 3.5 3-75, more 

 than 4 4.5 in length with caudal. As the largest specimen known 

 from the Aru-Islands is 92 mm. and considering the well known 

 variability in the height of these fishes, we don't think the 

 difference sufficient to keep them apart. 



3. Centratherina Tate Regan. 



(TATE REGAN, Trans. Zool. Soc. London XX. prt. 6, 1914, p. 283). 



Much compressed, elongate. Dorsal profile sloping down in 

 an almost straight line to snout. Ventral profile convex. Head 

 rather pointed, flat above. Upper jaw prominent. The inter- 



Fig. 81. Centratherina crassispinosa (M. Web.) X 3 /4- 



maxillaries are gently curved, without abrupt bent between 

 their horizontal and^ the lateral part. Lips thickened. Jaws with 

 several rows of pointed teeth, extending to the outside of the 

 INDO-AUSTRALIAN FJSHES IV. 20 



