GENERA OF MELANOT^NIIN^ 13 



e* Anal fin much elongate, its origin before, or not far behind, that of the 

 first dorsal ; first ray of both dorsals and of anal a strong pungent 

 spine (except in Rhadinocentrus) ; body typically very deep and 

 sharply compressed ; head depressed, and pointed. 

 f. All of the dorsal spines pungent; jaws and dentition as in Chila- 

 THERiNA. Fresh waters of northern New Guinea... A. Centratherina. 

 f. Only the first spine of both dorsals pungent. 

 g^. Lower jaw included ; gill-rakers few. 

 /i*. Mouth rather small, with a straight or slightly curved gape ; 

 anterior expansion of premaxillaries little developed ; teeth of 

 outer mandibular series enlarged, 

 t*. Inner band and outer series of teeth in lower jaw not separated 

 by an interspace; outer side of upper jaw with several series 

 of teeth projecting from the thick lip. Fresh waters of northern 



New Gtiinea 5. Chilatherina. 



i^. Inner band and outer series of teeth in lower jaw separated by 

 an interspace; outer side of upper jaw with few or no teeth. 



Fresh waters of New Guinea and Aru 6. Anisocentrus 



A^. Mouth rather large, with a curved gape ; premaxillaries with a 

 well developed anterior expansion ; series of teeth extending to 

 outer side of jaws ; outer series of teeth not enlarged. Fresh and 

 brackish waters of New Guinea and neighboring islands. 



7. Rhombosoma. 



g^ Jaws equal anteriorly, or the lower slightly projecting; anterior 



expansion of premaxillaries fitting an emargination in the lower 



jaw ; outer series of teeth in jaws enlarged ; teeth also present on 



vomer and palatines. 



y\ Scales large (32 to Z7), with edges nearly or quite entire; gill 



rakers of moderate length, 12 to 16 on lower limb of outer arch ; 



teeth in jaws conical. Fresh and brackish waters of Australia, 



Nezv Guinea, and neighboring islands 8. Melanot^nia. 



f. Scales small (55 to 60), with edges deeply crenulated ; gill-rakers 

 fine and long, 30 on lower limb of outer arch; teeth in jaws 

 stouter and more obtuse. Fresh waters of northern New Guinea. 



9. Glossolepis. 



/^ All of the fin spines flexible; lower jaw projecting; palate apparently 



toothless ; scales large, with edges nearly or quite entire. Fresh 



waters of Queensland 10. Rhadinocentrus. 



e^. Anal fin less elongate, placed well behind, or nearly opposite, the first 

 dorsal ; all of the fin spines flexible ; body less robust, approaching that 

 of Atherina in form ; head formed as in Atherina. 

 k^. Teeth strong, present on jaws, vomer, palatines, and tongue; spines 

 of dorsal, particularly the first, produced. Australia. 



11. Atherinosoma. 

 ^2. Teeth rather small, so far as known restricted to the jaws. 

 /^. Lower jaw projecting; second spine of spinous dorsal produced, 

 especially in the male; anal fin short, falcate. Fresh and brackish 

 waters of Australia, New Guinea, and neighboring islands. 



12. PSEUDOMUGIL. 



