2 6o Memoir Sears Foundation for Marine Research 



lb. Body moderately to very strongly compressed; chest and abdomen compressed 

 into a sharp keel armed with bony scutes. 



3 a. Median line of back in front of dorsal fin with ordinary or modified scales, 

 thus without a prominent median naked strip; stomach not gizzard-like, but 

 wall somewhat thickened in some species. 



4a. Pelvic fin well developed, inserted under base of dorsal, with 7—9 rays; 

 mouth gently oblique, the lower jaw usually included but occasionally 

 projecting; body moderately compressed. Subfamily Clupeinae. 



Virtually aU temperate and tropical 

 waters of the world, with some species 

 entering frigid zones; inhabiting salt, 

 brackish, and fresh water. 

 5 a. Vertical edge on rim of shoulder girdle (cleithrum) underneath free 

 edge of gill cover (opercle) smooth or even, without dermal lobes. 

 6 a. Back in front of dorsal fin with ordinary scales like those on 

 rest of body; pelvic with 8 or 9 rays; pectoral fin without a 

 free axillary process; scales not overlapping deeply, their ex- 

 posed part not much deeper than long, their margin slightly 

 irregular, not definitely serrate or pectinate. 

 7 a. Vomer with teeth; greatest depth of body about 4.0—5.0 

 in SL; ventral scutes weak, numerous, total number about 

 39—46. Clupea Linnaeus 1758, p. 274. 



7b. Vomer toothless; depth of body generally less than 4.0 in 

 SL; ventral scutes strong, total number about 27—38. 

 8 a. Upper margin of lower jaw within mouth rising gently; 

 teeth missing in examples 200 mm and upward in 

 length; cheek deeper than long (Fig. 69). 



Alosa Link 1790, p. 293. 



8 b. Upper margin of lower jaw within mouth rising 



abruptly; teeth present, at least in lower jaw, at all 



ages; cheek not deeper than long, definitely longer than 



deep in some species (Fig. 76). 



Pomolobus Rafinesque 1820, p. 312. 



6 b. Back in front of dorsal fin with a row of enlarged modified 



scales on each side of median line; pelvic with 7 rays; pectoral 



fin with a free axillary process; scales overlapping deeply, their 



exposed part much deeper than long, their margin strongly 



serrate to pectinate (Fig. 85). Brevoortia Gill 1861, p. 342. 



5 b. Vertical edge on rim of shoulder girdle (cleithrum) underneath free 



edge of gill cover (opercle) with two dermal lobes (Fig. 100). 



9 a. Last ray of dorsal greatly produced, filamentous, often reaching 



nearly or quite to base of caudal (Fig. 94); anal with 20-25 



rays. Opisthonema Gill 1861, p. 380. 



