CLUPEID^ THE HERRINGS 47 



mens in February in so sluggish a condition, that they were easily 

 dipped up with a net. 



The young are extremely different from the adult, slender and 

 minnow-like in shape, and with a row of fine teeth on the upper jaw, 

 although the mouth of the adult is entirely toothless and smooth. 

 The internal structure of the young also differs remarkably from 

 that of the full-grown fish, especially in the much greater simplicity 

 of the digestive apparatus, the intestine, in specimens not more than 

 an inch long, passing almost directly back from the stomach to the 

 vent. The food of the young consists, like that of most of our young 

 fishes, almost wholly of small crustaceans and insect larvae — the 

 animal plankton of our waters. That of larger specimens, on the 

 other hand, is very uniform in character, comprising quantities of 

 mud, with which the intestine is commonly packed from end to 

 end, mixed with many minute plants, and much vegetable debris. 

 Occasionally in the vicinity of distilleries, this fish feeds, like the 

 buffalo-fish, on distillery slops, and sometimes one will find univalve 

 mollusks, aquatic insects, and the like, sparsely represented in the 

 food. Half-grown specimens often contain larger quantities of the 

 plankton organisms than are found in the food of the adult. 



The flesh is coarse and not delicate in flavor, but still is not un- 

 palatable, and is eaten by some. In the Great Lake region this 

 species is often caught and offered for sale under the name of "lake 

 shad." It is seldom used in Illinois, however, but is systematically 

 picked out of the catch and thrown away by the fishermen, who 

 regard it as a nuisance rather than a benefit, commonly ignoring 

 its value as food for the species we most prize. 



Family CLUPEID^ 

 (the herrings) 



Body oblong or elongate, more or less compressed, covered with cy- 

 cloid or pectinated scales; head naked; belly rounded, or compressed and 

 serrated; lateral line wanting; skeleton osseous; vertebrae 40 to 56, an- 

 terior ones not modified; ventral fins abdominal; dorsal median or some- 

 what posterior; no adipose fin; caudal forked; mesocoracoid present; gill- 

 membranes free from isthmus ; gill-rakers slender ; branchiostegals usually 

 few (6 to 15) ; pseudobranchiae present; adipose eyelid present or want- 

 ing; mouth terminal, oblique; premaxillaries not protractile; maxil- 

 laries composed each of about 3 pieces, forming lateral margin of upper 

 jaw; teeth usually small or wanting, variously arranged; air-bladder 

 large, with open duct. 



