HERRING TRIBE. 487 



The Herring Tribe, — Family Clupeid^. 



Second to none in their commercial importance, the herring tribe are remark- 

 able for the enormous number of individuals by which several of the species 

 are represented rather than for the multiplicity of the species themselves; this 

 being probably one of the chief reasons for the great value of these fishes as a 

 food-supply. Although the existing representatives of the family may be readily 

 distinguished from the salmonoids by the absence of a fatty fin, yet extinct forms 

 indicate such an intimate connection between the two groups as to induce some 

 naturalists to include both in a single family. Whatever may be the ultimate 

 verdict on this point, in a work like the present, where we are mainly concerned 

 with living types, it is obviously preferable to follow the ordinary system. While 

 the typical representatives of the family have the parietal bones of the skull 

 separated by the supraoccipital and but one true tail-vertebra, in the genus Elops 

 the parietals are in contact, and there are two caudal vertebras. On this account 

 it has been proposed to make the latter genus the type of a distinct family ; a 

 similar proposal having been made in the case of an analogous departure from the 

 ordinary type among the salmonoids. In addition to the absence of the fatty fin, 

 most herrings are characterised by the presence of small bony plates on the lower 

 margin of the body. Externally the whole body is scaled, with the lateral line 

 mostly wanting ; while the head is generally naked, and the muzzle always without 

 barbels. The under surface is more or less compressed, and generally so much 

 so as to form a sharp edge, which is usually serrated. In the gill-cover the four 

 elements are present, and the gill-openings are in most cases very wide. Both 

 premaxillse and maxillae enter into the formation of the margin of the upper jaw, 

 but each of the latter bones is peculiar in being composed of three separate pieces. 

 The single short dorsal fin has a small or moderate number of weak rays, and the 

 anal may be many-rayed. The stomach is furnished with a blind sac; the air- 

 bladder is of more or less simple structure ; and well-developed false gills are usually 

 present. Distributed over all temperate and tropical seas, herrings are mainly 

 littoral fishes, none of them being inhabitants of deep water, and none truly 

 pelagic. Although the majority are marine, many of them will enter fresh water, 

 and some live permanently therein, while it is probable that all can be acclimatised 

 to such conditions. As might have been expected from their generalised structure, 

 herrings are an ancient group, the typical genus dating from the period of the 

 Chalk, while anchovies and other existing generic types are known from the 

 Eocene. A number of more less nearly allied Cretaceous genera appear to connect 

 the family very closely with the higher ganoids. 



The common herring {Clupea harengus) belongs to a group of 

 r up. g enera characterised by the equality in the length of the two jaws, 

 the presence of free fatty lids to the eyes, and the serration of the lower border of 

 the hinder part of the body ; the typical herrings being distinguished from the 

 allied genera by the anal fin being of moderate length, with less than thirty rays, 

 and the serration of the under surface commencing from the chest or point of 

 origin of the pectoral fins. Usually the scales are of moderate or large size, 

 although they may be small ; the cleft of the mouth is of medium width ; and if 



