332 THE THIGH AND LEG. [CHAI-. 



Among the INSECTIVORA, the Hedgehog has a. strong 

 ridge distally from the great trochanter of the femur, and 

 several other forms have a similar rudiment of a third 

 trochanter. As a general rule the fibula is slender, and in 

 its distal half ankylosed with the tibia, but it is complete 

 and distinct in the genera Galeopithecus, Tupaia, Centetes, 

 Ericulus and Solcnodon. 



In the CHIROPTEKA, the femur is slender and straight, 

 with trochanters of nearly equal size, and with a small 

 globular head, set on a very short neck, with its axis 

 pointing almost directly to the anterior or dorsal surfaces of 

 the bone. The fibula varies in condition ; in the Molossiiitf 

 alone it is well developed. In all other species it is either 

 very slender or ligamentous in its proximal third (Pteropns)^ 

 reduced to a small bony process above the heel, as in 

 Megaderma, or altogether absent, as in AJycteris (Dobson). 



In the RODENTIA the femur varies much. In the Hares 

 and Squirrels it is long and slender, with a third trochanter 

 immediately below the great trochanter. In the Beaver it is 

 broad and flat, and has a strong ridge about the middle of 

 the outer side of the shaft. In many other forms (e.g. 

 Hystrix) neither of these accessory prominences exist, but 

 the great trochanter is usually much developed. 



In Myopotamus and still more in Capromys there is a 

 strong ridge on the inner side of the middle of the shaft, 

 indicating the point of insertion of the adductor muscles. 



In some forms, as the Beaver, the fibula is distinct, 

 strongly developed, and separated from the tibia, except at 

 the extremities, by a wide inter-osseous space. In others, as 

 the Hares, it is slender, and in its distal half united with the 

 tibia. The patella is generally elongated, fabellie are usually 

 developed, and there are often wedge-shaped ossifications in 

 the semilunar cartilages of the knee-joint. 



