THE ANCIENT MAMMALS OF BRITAIN. 327 



detached teeth from the London clay under the name of Co?-}- 

 phodon, in allusion to the strongly marked oblique crest sur- 

 mounting their crowns. From nearly complete skeletons dis- 

 covered in America, we know that the Coryphodons, which 

 were animals with somewhat the proportions of a Bear, although 

 furnished with a well-developed tail, differed from both the Odd- 

 toed and Even-toed Ungulates in having five toes to each of the 

 very short and wide feet, and likewise in the structure of the 

 feet themselves. The molar teeth, too, as shown in figure Cof the 

 illustration (p. 324), are likewise quite different from those of any 

 living member of the Order, and are remarkable for the extreme 

 shortness of their crowns. The nearest allies of these animals 

 were the Uintatheres of North America, distinguished by the 

 presence of a large pair of tusks in the upper jaw, and the 

 two groups collectively constitute the order of Short-footed 

 Ungulates. 



One remarkable palate of a skull from the London clay 

 of Heme Bay, preserved in the museum at York, and described 

 under the name of Platychmrops^ has given rise to some amount 

 of discussion as to its serial position. It has been suggested, 

 however, that it belongs to a peculiar group of Mammals from 

 the North American Eocene, which combine many of the 

 characteristics of the Ungulates, Carnivores, and Rodents. Of 

 the latter order there are but small traces in the lower British 

 Tertiaries; but some lower jaws from the Hordwell and Headon 

 beds have been referred to the genus Theridomys, which is of 

 common occurrence in the corresponding continental strata, 

 and indicates an extinct Family of the Order Whales are like- 

 wise rare, but from the Barton beds there has been obtained a 

 skull belonging to the peculiar group of Zeuglodonts, which are 

 not improbably the ancestral types whence the modern toothed 

 Whales have been evolved. Unhke all existing members of 

 the Order, these extinct Cetaceans had double-fanged mol;r 



