384 PROCEEDINGS OF THE ACADEMY OF [1885. 



the shaft is cylindroid, and the condylar end is expanded in all 

 its diameters, but notably in its posterior diameter. Were a sec- 

 tion of the condyles made by extending downward the plane of 

 the posterior surface of the femur, the condyles would be removed 

 in such manner as to retain in the removed segment the base 

 of the inter-condyloid notch. If, however, the parts named be 

 examined in the sloth, in the genus Gylosthurus (the two-toed 

 arboreal ant-eater), in the bat and in the seal, the head of the femur 

 is seen to be without a neck, or to possess a very small one. The 

 shaft of the femur is flattened, and the condylar end is scarcely at 

 nil expanded. If a section be made as above described, the base 

 of the condyloid notch is not removed with the section. The 

 bone in its general features resembles the femur of the embryo. 



The fibula in the genera bearing the weight of the body, exhibits 

 two forms, one in which the bone is parallel to the tibia, and nearly 

 equal to it in length, and a second in which the distal end is either 

 anchylosed to the shaft of the tibia or is obliterated. In the genera 

 which are suspended by the feet, or are otherwise free from the 

 sustenance of weight, the fibula, when it departs from the type in 

 which it is separate from, but co-equal with the tibia, is always 

 reduced at the proximal end. In the seal the proximal end is 

 anchylosed to the shaft of the tibia; in the bat the proximal end 

 is entirely absent ; in the sloth the proximal end, while free, is 

 small, while the distal end is broad and highly specialized in 

 function. 



The astragalus is flattened and irregular in the t} r pes whose 

 posterior extremities sustain weight, but in those free from such 

 weight it is elongated. The tendency is seen in Galago and 

 Tarsuis, for both calcaneum and astragalus are seen to be elon- 

 gated, but the tendency is carried to an extreme degree in the 

 sloth, the bat, and in l'hoca vitulina. 



The manner of articulation in the gorilla of the fibula, with 

 both the calcaneum and the astragalus, was dwelt upon, as well 

 as the fact that the astragalus in that genus possesses a broad 

 deflected fibular facet. This peculiar projection is rudimental in 

 the astragalus of the skeleton of civilized man, but was found 

 highly developed in an astragalus from an Indian grave found at 

 Cooper's Point, New Jersey. 



The following was ordered to be printed : — 



