12 ATHERINID^: SILVERSIDES 



fairly evident in the actual type-specimen. They are inserted nearly mid- 

 way between base of pectoral and that of anal, under the fifteenth 

 vertebra.) 



The scales are large and round, without trace of apical teeth ; they 

 are evident over most of the body, and are about as numerous in median 

 series as the vertebrae. 



By including in the following key the ranges of the several sub- 

 families and the numerous genera comprising the family Atherinid^, 

 we indicate the main features of the geographical distribution of these 

 fishes. 



Analysis of the Living Genera of Atherinid.e. 



a\ Nannatherinin.e : Anal fin composed of three spines and eight or nine soft 

 rays, opposite the first dorsal and similar to it ; dorsal fins joined at base, the 

 first of eight or nine pungent spines ; pectorals symmetrical, rounded, placed 

 rather low ; the ventrals inserted near pectorals ; caudal rounded ; vertebrae 31 ; 

 body comparatively robust ; mouth wide, oblique, the maxillary exposed distally 

 and extending to below the eye; premaxillaries little protractile; teeth on jaws, 

 vomer, and palatines; gill-rakers reduced to short projections. Streams of 



Western Australia 1. Nannatherina. 



d^. Anal fin with a single spine, its origin usually in advance of that of second 

 dorsal ; dorsal fins separate, the first usually with fewer than eight spines, 

 usually flexible ; pectorals scythe-shaped, pointed, inserted high ; vertebrae, so 

 far as known, more numerous. 

 fc\ Bedotiin^ : Caudal fin truncate and rounded ; dorsal fins separated, the first 

 of five flexible spines, originating slightly in advance of anal ; anal fin com- 

 posed of a spine and 14 to 19 soft rays ; ventrals inserted not far behind 

 pectorals ; body rather robust ; head naked ; mouth large, extending to below 

 eye, lower jaw projecting; premaxillaries little protractile, the anterior part 



separated by a notch from the lateral. Streams of Madagascar 2. Bedotia. 



b'. Caudal fin forked ; head scaly, at least on sides ; premaxillaries fully protractile, 

 the anterior part not separated by a notch from the lateral. 

 c\ Dorsal fins rather closely approximated, the height of the first being much 

 greater than the disttance between the origins of the two fins ; body more 

 or less robust, and strongly compressed; vertebrae few (33 to 37 in genera 

 described). 

 d^. Rheoclin^: Dorsal fins very closely approximated, the first without 

 filamentous nor pungent spines ; anal fin of moderate length, with 14 to 16 

 soft rays ; belly rather short ; fewer than 12 conical gill-rakers on lower 

 limb of first arch ; mouth rather large, extending to below eye ; lower jaw 

 projecting; teeth on jaws, vomer, and palatines. Fresh waters of Mada- 

 gascar 3. Rheocles. 



d'. MELANOTiENHN^ : Dorsal fins usually less closely approximated (but not 

 widely separated), the first spine usually pungent, at least one of the 

 spines always filamentous in the male (except in Centratherina, in 

 which all of the spines are pungent); anal fin usually elongate; belly 

 more or less shortened. Fresh ivaters of Australia, Neiv Guinea, and 

 neighboring islands. 



