1000 CLASS PISCES. 



that it should not rather be placed in the allied American family 

 Hyodontidce. 



Family Esocid^e. — The Esocidcz are now represented by the Pikes 

 (Esox) of the rivers of the Northern Hemisphere. They are charac- 

 terised by the margins of the upper jaws being formed by the pre- 

 maxillse and maxillae ; by the presence of small conical teeth on the 

 palate ; and the absence of an adipose fin, and the position of the 

 dorsal in the hinder part of the body. Species of Esox occur in 

 the Upper Miocene of GEningen in Switzerland, and the Pleistocene 

 of Silesia ; while the extinct Sp/ieno/epis, of the Upper Eocene of 

 Paris and the Eocene of Aix in Provence, characterised by its 

 wedge-shaped scales, is considered to be allied. Recent, writers also 

 place in this family the marine Isticeus of the Chalk of Westphalia 

 and the Lebanon, in which there is a long dorsal fin occupying the 

 greater part of the back. 



Family Scombresocid^e. — The members of this family mainly 

 inhabit tropical and temperate seas, and are best known by the Gar- 

 pike (Be/one) and the Flying-fish [Exoccetus). The jaws are formed 

 as in the last family ; the dorsal fin is placed above the anal in the 

 caudal region, and there is no adipose fin. Belone is found in the 

 Miocene of Licata, in Sicily ; while Holosteus of the Middle Eocene 

 of Monte Bolca is an allied genus. The living genus Exoccetus is 

 characterised by the enormous development of the pectoral fins, and 

 was preceded in the Chalk of the Lebanon by the nearly related 

 Exoccetoides. 



Family Cyprinodontid^e. — The Cyprinodonts are mostly small, 

 carp-like fishes, inhabiting the fresh, brackish, or salt waters of a 

 considerable part of the world ; and readily characterised by the pre- 

 sence of scales on the head, and the absence of barbels. Species 

 of the type genus Cyprinodon (Zebias) occur in the Middle and 

 Lower Miocene of the Continent, while the CEningen beds have 

 yielded a species referred to the South American genus Pcecilia. A 

 comparatively large Cyprinodont has been described from the Plio- 

 cene of India. 



Family Cyprinid,e. — The important family of Carps is very 

 numerously represented in the freshwaters of the Old World and 

 North America. There are no scales on the head ; the margin of 

 the upper jaw is formed by the premaxillae ; there are no teeth in 

 the jaws ; there is no adipose fin ; the lower pharyngeal bones carry 

 one or more rows of teeth ; and the mouth frequently has barbels. 

 The body is more or less compressed, and is often comparatively 

 deep. In the Miocene of the Continent we have representatives of 

 the following genera now living in Europe — viz., Cyprinus (Carp), 

 Gobio (Gudgeon), Leuciscus (Roach and Dace), Tinea (Tench), 

 Rhodeus, which is mainly Asiatic, Aspius, and Cobitis. Acanthopsis, 



