1268 



CLASS MAMMALIA. 



presence of a minute third lower premolar. Liotomus of the French 

 Eocene differs from all the others by its smooth fourth premolar. 

 Menisc'oessus, from the uppermost or Laramie Cretaceous of the United 





Fig. 1 134. — Inner view of the left ramus of the mandible of Neofilagiaulax eoc&nus ; from the 

 Lower Eocene of Rheims. The line indicates the true size. (After Lemoine.) 



States, is a somewhat larger form which may probably be included in 

 this family. It was first made known by an upper true molar, but 

 secant premolars from the same deposits subsequently described 



under the name of Halodon, together 

 with other teeth figured under the names 

 of Trifiriodon, Diprodion, and Selenac- 

 odon, are probably all referable to Men- 

 isc'oessus. Another form from the Lara- 

 mie Cretaceous which may be provision- 

 ally known as Cimoliomys, appears to be 

 closely allied to the Eocene Ptilodus, but 

 may have affinity with Plagiaulax ; the 

 teeth described as Cimolodon and Nano- 

 mys, as well as one of those referred to 

 Halodon appear inseparable from this 

 form. Other generic names have been 

 applied to teeth of a more or less closely 

 allied type from the same deposits. 



Certain bones from the Laramie de- 

 scribed as Camfitomus probably belong 

 to this group, and are noteworthy as 

 showing a distinct coracoid and inter- 

 clavicle ; thus, if rightly referred and determined, clearly indicating 

 the Prototherian affinities of the Multituberculata. 



From the Tertiaries of Patagonia Dr Ameghino has described 

 certain remains under the generic names of Abderites, Acdestis, and 

 Palceotheutes, which are referred to this family, and are apparently 

 nearly related to the European genera. The genus Microbiotherium 



Fig. 1135- — The left ramus of the 

 mandible of Ptilodus medi&vus ; 

 from the outer (a), inner (b), and 

 oral (c) aspects : from the Puerco 

 Eocene of New Mexico. (After 

 Cope.) 



