•24 elopidj:. 



Prseifiaxillary single; a very large supratemporal 



bone ; symplectic absent ; opercular bones 



hidden tinder the skin ; gill-opening narrow . 2. MoRMrRma:, p. 29. 

 Prsemaxillary paired ; supratemporal bone small ; 



symplectic present ; tally with a double bony 



serrature 3. N0T0PTERID.E, p. 145. 



2. Ribs inserted on parapophyses ; pectoral fins folding against belly, like 

 the ventrals. 

 Pncmaxillary paired ; interoperculum and sub- 

 operonlum present ; ventral fins distant from 



the pectorals 4. Osteoglossid^e, p. 148. 



Prrcmaxillary single ; interoperculum and suboper- 



culum absent ; ventral fins near the pectorals . 5. PantoDONTID^E, p. 151. 



B. Supraoccipital in contact with the frontals ; suboperculum and interoper- 

 culum well developed. 



1. Gill-openings wide ; body covered with scales ; mouth not protractile. 

 Postclavicle on outer side of clavicle ; no adipose 



dorsal fin 6. Olufeice, p. 153. 



Postclavicle on inner side of clavicle ; an adipose 



dorsal fin 7. Salmonid^e, p. 165. 



2. Gill-openings narrow. 



Body covered with scales; interoperculum enormous, 

 covering the gular region ; mouth very pro- 

 tractile, superior 8. Phractol.emid.e, p. 167. 



Body scaly ; mouth not protractile, inferior ... 9. Kneriid^e, p. 169. 



Body naked ; mouth not protractile, inferior ; 



symplectic absent 10. Cromeriid.e, p. 173. 



Fam. 1. ELOPlDiE. 



Margin of the upper jaw formed by the prsemaxillaries and the 

 maxillaries, the latter much developed ; parietal bones forming a median 

 suture above the supraoccipital, or separating it from the frontals ; 

 symplectic present ; interoperculum and suboperculum well developed ; 

 an intergular or sublingual bone, between the rami of the mandible. 

 Pharyngeal teeth. Branchiostegal rays very numerous (more than 20). 

 Gill-openings wide. Ribs mostly sessile, behind a parapophysis ; epi- 

 neurals, no epipleurals. Pectoral fins inserted very low down, folding 

 like the ventrals. Ventral fins with 10 to 16 rays. 



Two genera, of wide distribution in tropical and subtropical seas : — 



Scales small ; dorsal a little longer tnan anal ... 1. Elops, L., p. 25. 

 Scales large ; dorsal a little shorter than anal, with 



the last ray much produced . 2. Meqalops, Lacep., p. 27. 



