150 Memoir Sears Foundation for Marine Research 



Key to Families of Clupeoidea, Known or to be Expected in 

 the Western North Atlantic 



I a. Tip of fleshy snout overhanging mouth. Engraulidae, p. 152. 



I b. Tip of fleshy snout not overhanging mouth; at most the upper jaw protruding a 

 little beyond lower. 



2 a. Shoulder close behind upper part of gill opening, with a conspicuous pro- 

 jecting tubular papilla, open at the tip. Searsiidae, p. 254. 

 2 b. Shoulder without projecting tubular papilla. 



3 a. Rear end of base of dorsal fin in advance of origin of caudal by a distance 

 as long as head (longer in most); sides silvery; swim bladder well devel- 

 oped. Clupeidae, p. 257. 

 3 b. Rear end of base of dorsal fin in advance of origin of caudal by a distance 

 considerably shorter than head; sides not silvery; no swim bladder. 



Alepocephalidae, p. 250. 



