504 



THE CAT. 



[chap. XIV. 



part of the trias and also in the oolite, including the Purbeck beds. 

 Such remains have been found in both Europe and North America, 

 and consist of the genera Microlesfes and Dromathermm. Microlestes 

 is a small insect-eating beast,'"' of which a few teeth have been dis- 

 covered. Dromatherium t is a small American mammal, the mandible 

 of which bore on each side three incisors separated by short intervals, 

 a canine, and ten teeth in a continuous series of premolars and 

 molars. 



Other mesozoic forms are Amphitherium, Amphilestes, Phascolo- 

 iherium, and Stercognatlms. 



Amphitherium J is a genus founded on a lower jaw, with three 

 incisors and a canine on each side, but with a series of twelve pre- 

 molars and molars. The angle of the mandible is not inflected in 

 Amphitherium. 



Amphilestes § is a form similar to the last, but with teeth more 

 bristling with pointed tubercles, suited for crushing the bodies of 

 insects. 



Fhascolothenum \\ had three rather separated incisors on each side of 

 its mandible, a canine, and a series of only seven teeth representing 

 the premolars and molars. The angle of the mandible was inflected. 

 Stereognathiis^ is an extinct form known by a portion of a 

 mandible (from the Stoncsfield slate) three quarters of an inch long, 

 with three teeth quadrate in form, each with three pairs of cusps, 

 and not distinctly resembling those of any existing group of animals. 

 These forms (except the last mentioned) have been generally 

 presumed to be marsupial, from their resemblance to certain 

 modern marsupials, such, e.g., as Myrmecohius, a small Australian 

 opossum, with a series of nine molars, a canine, and three rather 

 separated incisors on each side of the mandible. Some of these 

 fossil genera also present certain resemblances in the form of the 

 molar teeth, or in the position of the dental foramen, to American 

 opossums (the genus Bidelphijs) or to kangaroo-rats {ir//psij)ri/)nnHs). 

 The above are the yet known secondary mammalian forms. 



When we enter upon eocene strata we come at once upon a multi- 

 tvide of mammalian species now passed away, some of which it will be 

 well here briefly to pass in review for reasons which will appear in 

 the next chapter. Amongst eocene mammalia a group of fossils may 

 first be mentioned which have been associated together by Professor 

 Cope under the term Creodonta.*^' Some of these creatures had 



* See Owen's Paloeontology, p. 301. 



t L.c, p. 302. 



J See Owen's British Fossil Mammals, 



p. 29. 



§ Owen's Paloeontology, p. 303, and 

 Brit. Foss. Mam. p. 58 (Aiaphithcrium 

 Broderipii). 



II Owen's Falreontology, p. 304, and 

 Broderip, Zoological Journal, vol. iii., 

 p. 408, plate 40. 



II Owen's Palajontology, p. 308. 



** See Ins paper on Creodonta, read 

 before the American Philosophical Society 

 ill July, 1880. See also his paper on the 

 Flat-clawed Carnivora of the Eocene of 

 "Wyoming, in the Proceedings of the 

 American Philosophical Society, vol. xiii., 

 No. 90, 1873. See also Professor Flower's 

 Extinct Animals of North America, a 

 lecture delivered at the lioyal Institution 

 on March 10th, 1876. 



