442 UNGULATA 
was very small; the upper molars were tritubercular, while the 
lower ones had crescentoid ridges as in Paleotherium. The skeleton 
resembled that of the Carnivores, but the scaphoid and lunar bones 
were distinct, and there was a third trochanter on the femur. The 
feet were plantigrade, and each had five digits, all with long pointed 
claws. In the allied genus Stylinodon all the teeth were rootless. 
Some forms were as large as a Tapir. 
These, with other more or less closely allied animals, such as 
Calamodon and Psittacotherium, constituting a group called Teeni- 
odonta, are included by Cope in his large order Bunotheria, to which 
also the existing Insectivora are referred. The dentition of some 
of these forms makes a remarkable approximation towards a Rodent 
type, while it has been suggested that there are also signs of remote 
Edentate affinities. The constantly increasing knowledge of these 
annectant forms adds to the difficulty so often referred to in this 
work of establishing anything like a definite classification of the 
heterodont mammals. An incisor tooth from the Swiss Eocene 
has recently been referred to Calamodon. 
Bibliography of Tagulata.—In addition to the works and memoirs mentioned 
under the different sections of the order, the following may be referred to :— 
W. Kowalevsky, ‘‘ Monographie des genus Anthracotherium,” Palwontographica 
1873; Id. ‘‘Sur l’Anchitherium aurelianense et sur V’histoire paléontologique 
des Chevaux,” Meém. de U'Acad. Imp. des Sciences de St. Pétersbourg, 1873; Id. 
“On the Osteology of the Hyopotamide,” Philosophical Transactions, 1873; 
L. Riitimeyer, ‘‘ Versuch einer natiirlichen Geschichte des Rindes,” etc., Neue 
Denks. der allgem. Schweiz. Gesellsch. fiir Naturwissenschaften, 1867: 1d. “Die 
Rinder der Tertiiir-Epoche,” bhand. der Schweiz. Paléont. Gesellsch. 1877 and 
1878; Id. ‘‘ Beitriige zu einer Natiirliche Geschichte der Hirsche,” ibid. 1880-1881; 
C. J. Forsyth-Major, “ Beitriige zur Geschichte der Fossilen Pferde,” bid. 1880: 
M. Schlosser, ‘‘Beitriige zur Kenntniss der Stammesgeschichte der Hufthiere 
und Versuch einer Systematik der Paar-und Unpaarhufer,” Morph. Jahrb. 1886 : 
E. D. Cope, ‘The Perissodactyla,” mer. Natural. 1887; M. Pavlow, “ Etudes 
sur histoire paléontologique des Ongulés,” Bull. Soc. Imp. Naturalistes Moscow, 
1887-1890. W. B. Scott and H. F. Osborn, “‘The Mammalia of the Uinta For- 
mation,” Trans. Amer. Phil. Soc. vol. xvi. (1889). 
