14 ATHERINID^:: SILVERSIDES 



l". Lower jaw included; first spine of spinous dorsal produced; anal 

 fin of moderate length, rounded. Fresh waters of Celebes. 



3. Telmatherina. 

 c". Dorsal fins widely separated, the height of the first being less than the 

 distance between the origins of the two fins ; body slender, often not 

 strongly compressed ; vertebra more numerous, so far as described 37 to 56. 

 Coasts of all tropical and temperate regions, a feiv genera confined to. 

 fresh waters, 

 m^. Atherinin^ : Premaxillaries not dilated posteriorly, usually slender 

 throughout ; gape straight, little restricted at corner of mouth by mem- 

 brane between jaws (Atheriscus excepted) ; anus located far in advance 

 of its normal position immediately before anal fin (scarcely advanced in 

 Atherion and Iso) ; belly rather long; ventral fins less posterior in posi- 

 tion, their insertions nearer to upper angle of pectoral base than to origin 

 of anal fin ; anal fin usually short. IVcst Indies east-ward to the South 

 Sea Islands, 

 n^. Head scaled on sides and top, trunk wholly scaled ; body not sharply 

 compressed ; belly without a fleshy keel ; head not abruptly truncated 

 posteriorly; gill-slits wide; anal fin with 6 to 18 soft rays. 

 t>\ Anus scarcely advanced in position ; rows of sharp tooth-like spines 

 present on head; gill-rakers slender, in moderate number; mouth 

 small, the maxillary not reaching to below eye ; rami of mandibles 

 elevated within the mouth. Shores of the western Pacific. 



14. Atherion. 

 o'. Anus notably advanced in position ; no spines on head. 



q\ Gill-rakers slender and numerous (16 to 28 on lower limb of outer 



arch) ; mouth larger, the maxillary usually reaching to or beyond 



front of eye; teeth moderately fine in jaws, seldom lacking on 



vomer. 



/. Rami of mandibles not at all or very slightly elevated within 



the mouth, the upper edge being straight or nearly so ; pre- 



maxillary processes short and blunt, one-fourth to about 



one-half as long as the eye ; head large and broad ; the eye 



large ; the body moderately robust ; scales rather large, in 



32 to 45 series. West Indies to the South Sea Islands (more 



nearly restricted to the Tropics than is Atherina). 



15. Hepsetia. 

 r^ Rami of mandibles elevated within the mouth, tiie upper edge 



being sharply curved upward posteriorly ; premaxillary proc- 

 esses relatively long and slender, about one-half to quite as 

 long as eye ; head usually shorter and narrower, and the eye 

 smaller, than in Hepsetia; the body usually more slender; 

 scales moderate or small, in 40 to 75 series. IVesi Indies to 

 southern Europe and the South Sea Islands. 



16. Atherina. 

 q*. Gill-rakers rudimentary, 10 or 12 on lower limb of outer arch; 

 mouth smaller, the maxillary not reaching to front of eye ; teeth 

 microscopic in jaws, none on palate; rami of mandibles elevated 

 within the mouth ; scales very large, in 25 to 35 series. Fresh 

 waters of Australia. 



17. (18) Craterocephalus. 



