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1869.] especially was this resemblance apparent in the so-called "coracoid" (fig. 11), which seemed obviously to be a Dinosaurian ilium—and in the femur, the likeness of which to that of Megalosaurus is noticed by the able authors of the memoir themselves, and it has been subsequently referred to by Professor Owen (Palæontology, 2nd ed. p. 278) as "a Dinosaurian femur." It seemed to be highly desirable that these fossils should be examined anew; and in consequence of a communication to Mr. Saunders, they were placed at my disposal in the most obliging and liberal manner. On visiting the Bristol Museum, more than a hundred different specimens were spread before me, and I was able to select from among them illustrations of the structure of the skeleton of almost every part of the body of the "Thecodontosauria," and to obtain proof that these singular reptiles were in all respects Dinosauria.

I hope to publish an account of these remains, with full details and illustrations, in the Memoirs of the Survey. For the present I confine myself to the bones which, taken together with those already described, demonstrate the Dinosaurian affinities of the Thecodonts, and determine the relations of the latter with other Dinosauria.

In their well-known memoir, Messrs. Riley and Stutchbury founded the genus Thecodontosaurus upon an imperfect mandible, containing twenty-one teeth (which was apparently the total original number) in a series. These teeth, they say, are acutely pointed and flattened, and the anterior edge is curved backwards and serrated; the posterior edge is also slightly curved and strongly serrated, the serratures being directed towards the apex of the tooth. The middle teeth are the largest; and all the teeth possess a conical pulp-cavity (Pl. III. figs. 1 & 2). To a single specimen of a broadly lanceolate tooth, with serrations at right angles to the axis, they attach the name of Palæosaurus platyodon. Another solitary tooth of more elongated conical form they term Palæosaurus cylindrodon. The description of the teeth of Thecodontosaurus is perfectly accurate; but I can see no important difference, in the direction of the serrations or otherwise, between these and the tooth called Palæosaurus platyodon, which, I suspect, may belong simply to a larger Thecodontosaurus.

In the tooth termed Palæosaurus cylindrodon, on the other hand, the direction of the serrations is really at right angles to the axis of the tooth; and in its form, also, the tooth more resembles that of Megalosaurus, being elongated, with the posterior margin straight or slightly concave, while the anterior contour is convex. The sharp posterior median ridge of the tooth extends for the whole length of the crown, and is strongly serrated throughout. The anterior serrated ridge is visible in what remains of the upper part of the crown; but I am unable to trace it in the lower half of the front face of the enamel (Pl. III. fig. 3). I think it will be proper to