640 INSECTIVORA 



has four digits, of which the two outer are small, while the middle 

 ones are large, with immensely powerful claws. 



Extinct Types. The only fossil forms which can be referred to 

 the section of the Insectivora with tritubercular molars are the 

 Leptictidce, of the Eocene and Miocene of North America. This 

 family includes the genera Leptictis, Mesodectes, and Ictops, all of 

 which are regarded by Dr. Schlosser as true Insectivora, although 

 they were placed by Professor Cope with the Creodont Carnivora. 



Bibliography of Insectivora. Peters, Beise nach Mossambique Sdugeth. 1852; 

 Id. "Ueber die Classification der Insectivora," Monatsb. Akad. Wissensch. 

 Berlin, 1865, and other papers; Mivart, "On the Osteology of Insectivora," 

 Journ. Anat. and Phys. 1867, 1868, and Proc. Zool. Soc. 1871; Gill, "Synopsis of 

 Insectivorous Mammals," Bull. Geol. and Geog.' Survey, U.S.A. Washington, 

 1875 (includes a general bibliography of the order) ; Dobson, Monograph of the 

 Insectivora, Systematic and Anatomical, London, 1882-90. 



