398 MAMMALIA. 



period. The so-called Hyaena spelcea, which is generally 

 believed to have been identical with the surviving spotted 

 hyaena (H. crocuta) of Africa, first appears in the Cromer Forest 

 Bed of Norfolk and is represented by numerous remains in the 

 cavern and other Pleistocene deposits of England and Wales, 

 ranging as far north as the vale of Pickering in Yorkshire 

 (Kirkdale cavern). Like its contemporary, the extinct cave 

 bear, it does not appear to have reached Ireland. 



The most specialized existing family of Carnivora, the true 

 cats or Felidae, are also closely linked with the Viverroids both 

 by the living Cryptoprocta of Madagascar, and by extinct forms 

 from the Miocene of Europe. According to present knowledge, 

 indeed, they seem to have gradually evolved in the Old World, 

 first migrating to North America at the close of the Pliocene 

 period, and thence eventually reaching South America. Their 

 upper canine teeth are not excessively enlarged ; their pre- 

 molars are ultimately reduced to two in the lower jaw, to three 

 in the upper jaw ; and their molars are reduced to one above, 

 two below. The upper sectorial tooth has usually three lobes, 

 while the lower sectorial is simply a blade without an internal 

 tubercle. Procelurus from the Lower Miocene of St GeVand- 

 le-Puy, France, and Pseudcelurus from the Middle Miocene 

 of Sansan, France, may be mentioned among the ancestral 

 forms. Felis itself first appears in the Middle or Upper 

 Miocene of Europe, and is known by many characteristic 

 remains from the Lower Pliocene of Pikermi in Greece, 

 Maragha in Persia, and the Siwalik Hills in India. The 

 largest known form, the so-called cave lion (Felis spelcea}, was 

 common in Europe during the Pleistocene period and inhabited 

 Britain as far north as the vale of Pickering, Yorkshire 

 (Kirkdale cavern). It was probably only a variety of the 

 existing Felis leo of Africa and Asia. Species as large as 

 the lion are also known from the Pleistocene of North 

 America. 



Throughout the Tertiary formations from the Upper Eocene 

 onwards both in Europe and North America but especially on 

 the latter continent there are also remains of a remarkable 

 family of cats with a dentition still more specialized than that 



