326 



MAMMALIA. 



diastema between the first premolar and the canine, also a slight diastema 

 between the latter tooth and the outermost incisor. All the premolars 

 except the foremost are as complex as the molars (fig. 185) ; and the 

 hindermost lower molar exhibits a third or supplementary crescent 

 posteriorly. The canines are conical and somewhat larger than the 

 incisors, which are nearly uniform and with a cutting edge. There are 

 the usual 7 cervical vertebra?, a little longer than indicated in the original 

 restoration (fig. 186); next follow 16 dorsal and 7 lumbar vertebrae; and 

 the number of sacrals and caudals is uncertain. The blade of the scapula 

 is considerably expanded ; the deltoid crest of the humerus is not much 

 developed ; the radius and ulna are separate and about equally developed ; 

 and in the manus the median digit (in) is only slightly larger than nos. n 

 and iv, while there is usually a small rudiment of metacarpal no. v. In 



FIG. 185. 



Palaotlierium crassum; left maxilla with dentition, three-quarters nat. size. 

 U. Eocene (Gypsum) ; Montmartre, Paris, la 3a, three molars ; Ip 4p, 

 four premolars ; E, e, paracone and metacone ; i, i, protocone and hypocone ; 

 M, m, protoconule and metaconule. (After Gaudry.) 



the pelvis the ilium is not much expanded. The third trochanter of the 

 femur is connected with a prominent ridge ; the tibia is much stouter 

 than the fibula, and these two bones are sometimes fused together 

 distally ; the pes resembles the manus. Palceotherium was thus named by 

 Cuvier at a time when extinct genera of mammals were only just being 

 recognized, and when none were supposed to date back beyond the Eocene. 

 It is known not only by fragmentary remains from the Upper Eocene of 

 several localities in France, Switzerland, Bavaria, Wurtemberg, and the 

 Hampshire Basin, but also by one nearly complete skeleton embedded in 

 a slab of gypsum from Vitry-sur-Seine near Paris. The original specimens 

 studied by Cuvier were obtained from the gypsum quarries of Montmartre 

 near Paris. The largest species is Palceoth&rium magnum, about as large 



