SKELETON OF PROBOSCIDIA. 



443 



Pelvis of the Elephant, front 



Avith the trunk, fig. 162, 62, the ilia forming Avith the lumbar 

 series an angle of 120°: the ischium and pubis are short, and 

 form a symphysis, fig. 298, g, the axis of Avhich runs at an ano-le 

 of 100° with that of the ilium. This bone arches out from its 

 sacral joint almost transversely, the thick rough crista descendino- 

 with its angle, a, produced to a level Avith the acetabulum : the 

 anterior or abdominal surface is concave. The ischium, /, has 

 the tuberosity, e, directed 

 dorsad : the pubis shoAvs 

 a pectineal ridge, h. The 

 sciatic notches are AAadely 

 open : the obturator fora- 

 mina are smaller than the 

 acetabula, the planes of 

 which incline from the per- 

 pendicular about 70°, — a 

 favourable position for trans- 

 mitting the Aveight upon 

 the heads of the femora : 

 these, as in the Megathere, 

 have no round ligament, and 

 the acetabulum is simplified 

 accordingly. In a young Elephant I have observed an accessory 

 pelvic ossicle Avedged betAveen the ischium and pubis behind the 

 acetabulum. 



The great trochanter does not rise so high as the head of the 

 femur : the small one is almost obsolete : the post-trochanterian 

 fossa is shalloAv: the shaft, figs. 162, 297, 65, is straight, simple, 

 and compressed from before backAA^ard. The rotular trochlea is 

 subsymmetrical, occupying one-third of the breadth of the distal 

 end : the condyles are divided by a deep popliteal cavity. The 

 proximal epiphysis consists of the part forming the articular ball 

 and that forming the trochanter. The medullar}^ artery enters 

 the back part of the loAver third of the shaft, and ascends to a 

 very small medullary cavity. 



The tAA^o proximal articular surfaces of the tibia, ib. 66, are 

 transversely oval, separated by a conical prominence : there is a 

 large rough depression in front of the head of the bone : the 

 middle of the shaft is triedral, the hinder surface is very concave 

 superiorly. The distal articular surface is semicircular, convex 

 behind, and rising externally on the shaft to give articulation to 

 the fibula. The medullary artery passes transA^ersely from the 

 back of the shaft forAvard to a small medullary cavity. The 



