60 MIOCENE FAUNA. 



one species (Rhodeus amarus) occurs in Central Europe, whilst 

 CEningen had four species. They are small fishes with large 

 heads and short broad caudal fins. 



Next to the pikes, the tenches are the largest fishes of CEnin- 

 gen. They are characterized by their stout form of body, small 

 scales, and short broad fins. Only one living species is known, 

 and this belongs exclusively to Europe ; CEningen, however, 

 possessed three species, one of which (Tinea magna, Winkl.) at- 

 tained a length of more than a foot. 



The family of the Cyprinodontes is not represented on the 

 northern side of the Alps. It consists of small fishes belonging 

 to the warm and torrid zones, five species of which inhabited 

 the Lake of CEningen. The principal genus is Lebias, the four 

 species of which are, next to the Leucisci, most frequently met 

 with at CEningen. They occur, however, only in the insect-bed 

 in the lower quarry, where several specimens often lie close 

 together ; these fishes therefore, like their congeners, probably 

 lived together in shoals. The little Pcecilia, distinguished by 

 having a rounded caudal fin and the dorsal and ventral fins 

 placed very far back, are much less common. 



The two species of pike found at CEningen are very like the 

 common pike, which is distributed all over Europe, Asia, and 

 North America ; but they have much larger scales. The most 

 abundant species (Esox lepidotuSj Ag.) has a somewhat broader 

 body and longer head, but it attained the same size. Specimens 

 of all sizes, from 6 inches to 3 feet long, have been found. The 

 second species (E. robustus, Winkl.) is shorter and thicker, and 

 had smaller fins; it would therefore be a more clumsy fish. 

 That these pikes followed the same predaceous mode of life as 

 the existing species, is proved by some of the specimens, in the 

 abdominal region of which there lie the skeletons of smaller 

 fishes which they had swallowed. In the case of an eel (An- 

 guilla elegans, Winkl.), which had swallowed a small Leuciscus 

 (L. ceningensis) , the skeleton remained within the eel. The 

 heads of these swallowed fishes are always directed backward, 

 proving that they were seized in front. Eels were common in 

 the Tertiary period ; six species are known from Monte Bolca, 

 one from Aix, and two from CEningen, all of which differ con- 

 siderably from the single European species. 



