fig. 2, _g_) projects as an obtuse ridge above the ischiadic foramen and the succeeding expanded and confluent part of the ischium (ib. 63), which is vertically concave externally: the ilium, ischium, and pubis (ib. fig. 1, 64) have completely coalesced around the acetabulum. The pubis, which in this part is 7 lines thick, contracts as it becomes free to a diameter of 4 lines; it is smooth and convex below, and has been broken off near the acetabulum on both sides; the fracture shows its pneumatic structure. The ischium, as it recedes from the acetabulum, contracts to a trihedral column, with a vertical diameter of 4 lines; it is concave outwardly, convex inwardly, and suddenly expands below, about an inch from the acetabulum, to form part of the posterior boundary of the obturator foramen (ib. fig. 1, _f_), which is 9 lines in length, and is situated one half in advance of, and the other half beneath, the ischiadic foramen (ib. _m_). This latter is oval, with the large end forwards, 1 inch 3 lines by 10 lines in its principal diameters. Behind this foramen the ischium is confluent with the ilium for an extent of 2 inches, or perhaps rather more, as the posterior margin of the pelvis is not entire in any of my specimens. The inner surface of the ischium forms a low, obtuse longitudinal ridge towards the pelvic cavity, losing thickness as it recedes from the acetabulum. The chief pneumatic foramina in the pelvis are on the inner surface, above the acetabulum, behind the trochanterian articulation, and behind the iliac confluence of the last sacral pleurapophyses,—also at the hinder part of the ilium, on each side of the transverse buttress (ib. _e_) near its posterior junction with the ischium. The prærenal fossa (between _pl_ 4 & _pl_ 8, fig. 1) is deep and subdivided by the diapophysial plates: the postrenal fossa is wide and shallow. _Sternum._ (Plates III., IV., VI., XI.)