372 BUREAU OF AMEEICAISr ETHNOLOGY [bull. 52 



The linea aspera descends straight from the third trochanter and 

 the gluteal ridge as a marked postero-external border to the middle 

 (in length) of the shaft, where it bifurcates, one well-developed ridge 

 extending downward and slightly forward along the lateral aspect of 

 the shaft to the pronounced plantaris tuberosity, while the other 

 descends near the median line of the posterior surface, and at about 

 the junction of the lower with the middle third of the bone divides 

 into the medial and lateral epicondyhc lines, of which the former is 

 the more noticeable. The situation of the upper two-thirds of the 

 linea aspera is much more lateral than in man or in any of the apes 

 but is practically identical with that in many of the carnivores. 



The nutritive foramen in the Tetraprothomo is situated 8.9 cm. 

 above the lowest part of the external condyle, apparently near the 

 middle of the bone. It is located close to the median lip of the linea 

 aspera. In the femur of the Bolivian bear at the Museo Nacional the 

 foramen is 8.5 cm. above the external condyle, the total "bicondylar" 

 length of ^he bone being 17.4 cm., hence in very much the same 

 position as in Tetraprothomo, but is placed more toward the middle of 

 the posterior surface of the bone. The latter is also i^ue of the jaguar 

 and ocelot; in a jaguarondi and a coyote the canal was found placed 

 both in height and laterally much as in the femur from Monte Her- 

 moso. In man there are in most cases two canals for the nutrient 

 arteries, one situated near the middle and the other, more constant, 

 near the junction of the middle and superior thirds of the shaft, the 

 upper one often in the linea aspera, the lower one in or near its medial 

 lip. In most of the anthropoid apes and monkeys the canal appears 

 to be situated near the upper third of the bone, in or near the median 

 lip of the linea aspera and about the middle of the posterior aspect of 

 the bone. 



Below, a short distance (14 mm.) above the upper termination of 

 the trochlea, the shaft presents a distinct shallow patellar fossa. This 

 fossa measures about 9 mm. in length, 8 mm. in breadth, and 1.5 mm. 

 in maximum depth. A very similar fossa was found by the writer in a 

 chimpanzee, a baboon (C. porcarius), and a cinnamon bear. In a 

 striped hyena a marked depression exists immediately above the 

 trochlea. In a Canis mexicanus (No. 1384, U. S. National Museum) a 

 shallow fossa exists 12 mm. above the trochlea, hence in about the 

 same position as in the Tetraprothomo, and there is an additional large 

 depression just above the trochlea. No fossa exists in the gorilla, orang, 

 or gibbon. In a few American monkeys a slight hollow is found just 

 above the trochlea. In man there is immediately above or very near 

 the trochlea a more or less marked depressed surface, with some larger 

 vascular foramina, but this surface is never clearly defined and never 

 constitutes a distinct fossa as seen in the Tetraprothomo. 



