434 ORDER MALACOPTERYGII ABDOMINALES. 



membranous projection, which represents the adipose 

 fin of the salmones. Their maxillaries form the sides 

 of their mouth. 



We have two species which may one day form the 

 types of two subgenera. 



Stemoptyx diaphana, Hermann. Naturforscher, 

 fascic, xvi. pi. viii. copied, Walbaum,Arted. renov. tome 

 iii. pi. i. fig. 2. The teeth even, small, and crowded, and 

 five rays to the gills ; its form is singularly oblique, 

 the mouth even coming out beyond the vertical line. 



Stemoptyx Olfersii, C. ; has hooked teeth, and nine 

 rays to the gills ; both are found in the warm parts of 

 the Atlantic Ocean \ 



The fifth family of Abdominal Malacopterygii, or 

 that of 



CLUPEA, 



Is easily recognized by the absence of the adipose 

 dorsal ; the upper jaw is formed as in the trouts, at 

 the middle by intermaxillaries without pedicles, and 

 on the sides by the maxillaries ; their body is always 

 very scaly. The greater number have a natatory 

 bladder, and numerous cceca. A portion of them only 

 ascend into rivers. 



1 Our descriptions are from nature. Herman denied the existence 

 of branchial and ventral rays in his species, but his individual, 

 which is still to be seen at Strasburgh, exhibits both. We shall 

 treat more in detail concerning them in our great history of fishes. 



