Page:The Osteology of the Reptiles.pdf/170

The ilium is firmly connected with the sacrum, and there is a pubic foramen; the pubo-ischiatic notch is small. In the Plesiosauria (Figs. 125, 126), the slender ilium, connected ligamentously with a sacrum of three or four vertebrae, articulates at its distal extremity with the

Fig. 125. Pelvic girdle of Trinacromerum osborni, an Upper Cretaceous plesiosaur, from above: p, pubis; is, ischium; il, ilium.