442 UNGULATA 



was very small ; the upper molars were tritubercular, while the 

 lower ones had crescentoid ridges as in PaUeothenwn. 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 Tseni- 

 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 Eodent 

 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 Ungulata. In addition to the works and memoirs mentioned 

 under the different sections of the order, the following may be referred to : 

 "\V. Kowalevsky, "Monographic des genus Anthracotherium," Palceontographica 

 1873; Id. "Sur 1'Anchitherium aurelianense et sur 1'histoire paleontologique 

 des Chevaux," Mim. de I'Acad. Imp. des Sciences de St. Pttersbourg, 1873 ; Id. 

 "On the Osteology of the Hyopotamidre, " Philosophical Transactions, 1873; 

 L. Riitimeyer, "Versuch einer natiirlichen Geschichte des Rindes," etc., Neue 

 Denks. der allgem. Schweiz. Gesellsch. fur Naturwissenschaften, 1867; Id. "Die 

 Kinder der Tertiar-Epoche, " Abhand. der Schweiz. Paldont. Gesellsch. 1877 and 

 1878 ; Id. "Beitrage zu einer Natiirliche Geschichte der Hirsche," ibid. 1880-1881 ; 

 C. J. Forsyth-Major, "Beitrage zur Geschichte der Fossilen Pferde," ibid. 1880 ; 

 M. Schlosser, "Beitrage zur Kenntniss der Stammesgeschichte der Hufthiere 

 und Versuch einer Systematik der Paar-und Unpaarhufer, " Morph. Jahrb. 1886 ; 

 E. D. Cope, "The Perissodactyla," Amer. Natural. 1887; M. Pavlow, "Etudes 

 sur 1'histoire paleontologique des Ongules," Bull. Soc. Imp. Naturalistcs Moscoic, 

 1887-1890. W. B. Scott and H. F. Osborn, "The Mammalia of the Uinta For- 

 mation," Trans. Amer. Phil. Soc. vol. xvi. (1889). 



