426 THE SUCCESSION OF THE VERTEBRATE FAUNAS. 



time, species of Mastodon and true Equus occur, and there are 

 also llamas and peccaries. 



The latest (Upper) Pliocene mammalian fauna of Europe is 

 nearly similar to that of the Pleistocene, most of the genera 

 being identical and the species only slightly different. It is 

 best known from freshwater and estuarine deposits in the 

 Val d' Arno, Tuscany; from a torrent-deposit at Olivola in 

 the Carrara mountains ; from Perrier, Arde", Peyrolles and other 

 localities in the Puy-de-D6me, France; from Roussillon and 

 Montpellier (Herault), where the Lower and Upper Pliocene 

 faunas are not quite clearly distinguished ; and from the 

 Norwich Crag of Norfolk. There are still traces of the apes 

 in southern France and Italy. Among the Carnivora, Hycen- 

 arctos is just becoming extinct, and is being replaced by small 

 bears of the genus Ursus ; while the species of Machcerodus 

 are now very large. The true beavers (Castor) and other 

 characteristic modern genera of Rodentia appear for the first 

 time, and there is a large beaver-like animal, Trogontherium. 

 Mastodon occurs for the last time, and Elephas now appears 

 with the gigantic E. meridionalis. There are also true oxen 

 (Bos, Leptobos) and deer of existing genera (Gervus, Cervulus) ; 

 while a typical hippopotamus, as large as the recent H. amphi- 

 bius, is not uncommon. The tapirs have already disappeared, 

 but rhinoceroses survive (JR. etruscus} ; and for the first time 

 there is a completely evolved one-toed horse (E. stenonis). 



The Crorner Forest Bed. 



At the close of the Pliocene period Britain was still con- 

 nected with the adjoining continent, and an interesting remnant 

 of the mammalian fauna of this part of Europe at the time is 

 preserved in an old land surface and associated deposits now 

 exposed in the cliffs of Norfolk, especially in the neighbourhood 

 of Cromer. This is the so-called Forest Bed Series. The 

 mammals found here are chiefly those of the typical Pleistocene 

 fauna ; but a few still survive from the Upper Pliocene, such as 

 a gazelle, some deer with very large antlers allied to the Cervus 

 dicranius of the Val d' Arno, Rhinoceros etruscus, Elephas 

 meridionalis, and Trogontherium. The Forest Bed fauna is 



