io8 Memoir Sears Foundation for Marine Research 



and tip of Lower jaw projecting as far as tip of upper jaw or slightly beyond it; upper 

 jaw in others (Albula, Dixonina, Pterothrissus) falling far short of front of eye, and tip 

 of snout overhanging mouth. Maxillaries forming part of margin of upper jaw in 

 most but excluded from gape in a few {Albula^ Pterothrissus). Branchiostegal rays 

 slender, rod-like, not forming a part of opercular system. One to three lateral sensory 

 Canal-bearing bonelets on either side of snout in front of lacrimals. Some with two 

 rows of valves in cone of Heart {Albula., Pterothrissus^ and Megalops., but not Elops). 



There is a ribbon-like (leptocephalus-like) larval stage. 



Families. Three families are recognized here within the Suborder as defined 

 above: Elopidae, Albulidae, and Pterothrissidae, the last of which is extralimital and 

 is included only in the Key to Families. 



Fossil History. The Elopidae are known from as far back in geologic time as the 

 Lower Cretaceous, the Albulidae (including the Pterothrissidae) from as far back as 

 the Upper Cretaceous. 



Key to Families 



I a. A bony (gular) plate in chin region between branches of lower jaw; upper jaw 

 extending rearward considerably beyond eye; tip of lower jaw projecting at least 

 as far as tip of upper jaw, or a little farther; 23—35 branchiostegal rays. 



Elopidae (including Megalopidae of Matsubara), p. iii. 

 I b. No gular plate; upper jaw falling short of front of eye; tip of snout overhanging 

 mouth; only about 11— 15 branchiostegals. 



2 a. Base of dorsal occupying only about 25''/o of distance between gill opening 

 and base of caudal. Albulidae, p. 132. 



2 b. Base of dorsal occupying about So'/o of distance between gill opening and 

 base of caudal. Pterothrissidae. 



Plentiful off tropical West Africa 

 in depths of 100-250 m and re- 

 ported down to 500 m;'' also 

 Japan. 



4. According to Cadenat (j: 365) and Poll {2: 23). Not yet reported for the western Atlantic but may be expected 

 there. 



