UNGULATA. 349 



been about as large as a rhinoceros. Its remains occur in the Upper 

 Eocene and Lower Miocene of northern Italy, Switzerland, Bavaria, Hesse 

 Darmstadt, and France (Phosphorites of Quercy). Other species, some 

 comparatively small, are found in strata of the same age in central and 

 southern Europe as far east as Dalmatia. Detached teeth, apparently of 

 this genus, also occur in the Lower Pliocene (Siwalik Formation) of India ; 

 and portions of jaws with dentition are known from the Lower Miocene 

 (White River Formation) of Dakota. 



Hyopotamus <>r Ancodus (figs. 199, 200). Closely resembling A nthra- 

 cotherium in all parts of the skeleton, but less robust. The facial portion 

 of the skull is very slender, while a considerable diastema separates pm. 1 

 (when present) from the canine, usually also from pm. 2. The crescent- 

 shaped cusps of the molars are somewhat deepened. The best-known 

 species, H. velaunus, from the Lower Miocene of Ronzon, France, and from 



FIG. 1JU. 



Hyopotamus bovinus ; right upper molar 3, nat. size. L. Miocene (Hempstead 

 Beds) ; Isle of Wight. (After Lydekker.) 



the Hempstead Beds of the Isle of Wight, has a skull about 0'35 m. in 

 length. Teeth of a larger form, H. bovinus (fig. 199), are also common in 

 the Hempstead Beds, and have been found near Barcelona in Spain ; and 

 the largest known tooth, apparently of this genus, was discovered in 

 the Lower Pliocene (Siwalik Formation) of India (If. giganteus). Other 

 portions of skull and dentition, perhaps also certain limb-bones, are known 

 from the Siwalik Formation of India. Nearly complete skeletons have 

 been found in the Lower Miocene (White River Formation) of Dakota; 

 and there are at least two species, one destitute of upper pm. 1 (H. 

 americanus), the other (fig. 200) with upper pm. 1 and pm. 2 in contact 

 (H. brachyrhynchus). The last-mentioned species is proved to have 

 possessed a pentadactyl manus, with the digit no. I not only complete 

 but well developed. 



Merycopotamus. Known by the skull, mandible, and dentition ; also 

 probably by many detached bone-fragments which have been referred to it. 

 The genus is much like Hyopotamus, but the upper molars exhibit only 



