80 PHYSIOLOGICAL SERIES. 



extending from the transverse ligament to the articular 



o a 



cartilage of the head of the femur. 



(No depression can be seen on the head of the femur in 

 the dried bone.) 



B. 156. The right os innominatutn and femur of the Two-toed 

 Sloth (Cholop.pns didactylus). The hip-joint is laid open to 

 show absence of the ligamentum teres. 0. 0. 255 H. 



B. 157. Upper part of the femur of a Two-toed Sloth (Cholcepits 

 didactylus). There is no ligamentum teres, but upon the 

 femur head there is a flattened area, at the spot where 

 in other mammals the ligament when present is usually 

 attached. 



B. 158. Left half of the pelvis and upper part of the femur of a 

 Three-toed Sloth (Bradypus tridactylus) . The joint-cavity 

 has been opened to show the entire absence of a ligamentum 

 teres. 



B. 159. Right hip-joint of an Armadillo (Dasypus sexdnctus). 

 The joint-cavity has been exposed to show the great size of 

 the ligamentum teres. It has an extensive origin from the 

 anterior margin of the cotyloid notch and from the capsule 

 in its neighbourhood. 



B. 160. Right hip-joint of a young Pangolin (Manis penta- 

 dactyla}. The ligamentum teres is absent. 



Presented l>y Dr. J. Anderson. 



B. 161 Right hip-joint of a fetal Elephant (Eleplias africanus). 

 The ligamentum teres is absent. 



B. 162. The head of the right femur of an Elephant (Elephas 

 indicus] three years old. 



The cartilaginous articular surface is uniformly smooth, 

 having no depression for the insertion of the ligamentum 

 teres. 0. C. 255 E. 



B. 163. Left hip-joint of Procavia [Hyrax] capensis. The liga- 

 mentum teres is fused with the capsular ligament. 



