Plesiosaurus homalospondylus. Fig. 1. Skeleton, about 1-10th nat. size. Fig. 2. Thirteenth cervical vertebra of ditto, side view., nat. size. 2a. lb., section of neural spine, ib. Fig. 3. Ib., posterior surface of centrum, ib. Fig. 4. Fourteenth cervical vertebra, under view, ib. Fig. 5. Centrum of third cervical vertebra, side view, ib. Fig. 6. Ib., posterior surface, ib. Fig. 7. Centrum of eighth cervical vertebra, under view, ib. From the Upper Alum Shale, Lias, Whitby. In the British Museum.