390 



the ischio-cotylar ( 88« ) tuberosities. The margin subsides between the two last-named 

 prominences, and becomes thinner between the two first. The cotylar pit (#) and notch 

 {y) are deep. 



In the development of the Macropodal pelvis (PI. LXXI. fig. 3) three epiphyses 

 appear. One of these (ib. u-t') belongs to the acetabular end of the pubis, and becomes 

 the pubo-cotylar tuberosity (ib. fig. 1, 64*) ; a second belongs to the symphysial ends of 

 the pubis, and forms the haemal projection at the fore part of the ischio-pubic sym- 

 physis ; a third epiphysis (ib. fig. 3, It') belongs to the symphysial ends of the ischia, 

 and forms the haemal prominence at that end of the symphysis. 



The epiphysis (Jc) gives attachment to the entobasilar articular end (ib. fig. 1, r, r) 

 of its marsupial bone from this part and the ectobasilar process (s) ; the bone decreases 

 in breadth to the free (t) extremity. An oblique low ridge runs along the outer surface 

 of the pelvic end of the bone ; the rest is a thin plate with a sharp edge at the outer or 

 lateral border. 



The characteristics of the femur in the Kangaroos are : — 1, the height of the great 

 trochanter, which seems due to a superimposed additional and ankyiosed tuberosity 

 (PI. LXXIII. figs. 1, 2, 3 )( /'), divided by an antero-internal constriction from the part 

 below ; 2, the length and strength of the small trochanter (ib. n) ; 3, a rough, well- 

 defined tract (p) from the middle of the hind surface (fig. 2) of the shaft, outstanding, 

 in large species, like a " third trochanter ;" 4, the rough depression (ib. figs. 2, 3, y) 

 above the outer condyle (ib. v) ; 5, the great transverse extent of the articular surface 

 of that condyle by the production of its outer part, changing there the convexity into 

 a concavity transversely (fig. 2, v). With these may be noted the length and depth of 

 the post-trochanterian fossa (fig. 2, I). 



In M. rufus there is a small tuberosity (fig. 3. g) a few lines below the pointed 

 termination of the ectotrochanterian ridge (ib. h). The medullarterial hole is at the 

 inner side of the hind tuberosity (p) : the canal leads downward and inward. A 

 " linea aspera " is continued from the small trochanter (e) two thirds of the way down 

 the inner side of the shaft. The convex fore part of the outer condyle (fig. 1, s) is 

 prominent ; the rotular (r) and condylar (s, t) surfaces are continuous. 



In M. rufus, as in M. major, the tibia is nearly twice the length of the femur. Its 

 head (PI. LXXIV. fig. 4) is peculiar for the excess of antero-posterior over transverse 

 diameter; the outer facet of the triedral shaft (ib. fig. 1, Jc) is more remarkable for its 

 deep excavation, and the sharpness and production of the ridges dividing it from the 

 inner and hinder facets : but these characters are limited to the proximal half of the 

 bone ; at the distal half the surfaces are more or less flattened and the dividing angles 

 rounded ; the anterior one, a continuation of the proximal procnemial ridge (h), is least 

 so ; and the hind facet of the distal half (ib. fig. 6) is feebly concave across. 



In fig. 4, a is the outer articular surface, b is the inner articular surface, and c is 

 the " spine." This rises 3 lines in advance of the intercondylar notch (y), to a height 

 of 5 lines ; the fore and-aft extent of its base is 11 lines. The fore part of the head of 



