272 COPE. (Vou. IIL. 
2. Torsion only. 
Alternation of carpal bones in Anthropomorpha. 
Rounding of head of radius in Edentata and Anthropomorpha. 
Symmetrical flanges of ulnar cotylus in Anthropomorpha. 
Unsymmetrical flanges of ulnar cotylus in most Mammalia. 
Involution and sculpture of zygapophyses of Diplarthra. 
3. Torsion and impact without flexure. 
Alternation of carpal and tarsal bones in Ungulata. 
4. Torsion, impact and flexure in one plane. 
Tongue-and-groove joint in humerus of Diplarthra. 
Tongue-and-groove joint in metapodials of all orders. 
Tongue-and-groove joint in phalanges of Edentata, Insectivora, 
etc. 
5. Flexure in two planes. 
Saddle-shaped cervical vertebrze in Quadrumana. 
6. Flexure in several directions. 
Ball-and-socket vertebral articulations. 
Head of humerus. 
Head of femur. 
AA. Motion not in Articulation (Teeth). 
7. Displacement by crowding. 
Tritubercular molars. 
8. Transverse thrust. 
The V’s in molars of both jaws in various orders. 
9g. Longitudinal thrust. 
The V’s in the molar teeth of the Multituberculata. 
Obliquity of molars in many Rodentia. 
10. Stimulation of pressure and strain. 
Prismatic molars of Diplarthra, Rodentia, etc. 
Sectorial teeth of Carnivora, 
