The sutures presented characters similar to those exhibited by immature birds; and he thought that the separation of the bones in this example showed affinities to the anserine type. He was quite prepared to regard the fossil as that of a bird rather than of an Ornithosaurian. He inquired as to the character of the palatal bones.
Mr. Charlesworth inquired as to the light in which this discovery would be regarded by evolutionists.
Prof. Owen briefly replied.
[Plate XVIII.]
In 1849 a block of sandstone containing a considerable portion of a reptilian skeleton was found by some labourers on the south-west shore of the Isle of Wight, near Cowleaze Chine. It was broken in two; and one piece passed into the collection of the late Dr. G. Mantell, the other into that of Mr. Bowerbank. Subsequently both pieces were acquired by the British Museum and reunited. Thus completed, the slab exhibits a continuous chain of some 18 pre- sacral vertebræ, succeeded by the right ilium, the middle of which is crushed and hidden by an imperfect metatarsus. Below this are some long slender bones, which have received different interpretations from distinguished anatomists; and behind these are the left femur and a series of 12 caudal vertebræ. In 1855 a description of this fossil, illustrated by a plate, was given by Professor Owen, in his 'Fossil Reptiles of the Wealden Formations' (vol. 1855, Older Dinosauria, p. 2), where it is entitled "Part of the Skeleton of a young Iguanodon, I. Mantelli,"—a conclusion towards which the weight of evidence then seemed to incline. In 1867 Prof. Huxley, from a comparison of its vertebræ with those of Iguanodon, and from the presence of four metatarsals in the pes, concluded its generic distinctness from Iguanodon Mantelli; and in 1870 he made it the subject of a communication to this Society. Prof. Huxley prefaced this paper by a detailed description of a small reptilian skull dis- covered by the Rev. W. Fox in the same stratum from which the Mantell-Bowerbank fossil had been obtained. It had been previously exhibited by Mr. F. Fellows for Mr. Fox, at the Norwich Meeting of the British Association, 1868, when Mr. Huxley drew attention to the remarkable facts that the teeth contained in the posterior moiety of the præmaxilla were quite different in shape from the maxillary teeth, and that the anterior moiety of the præmaxilla was beak-like and edentulous. The maxillary teeth, though presenting a general resemblance to those of Iguanodon, at the same stage of wear, yet appeared, on close examination, so distinct as not to leave any doubt of the generic distinctness of this reptile; and Mr. Huxley proposed for it the generic name Hypsilophodon, and called the species H. Foxii, after its fortunate discoverer. The preservation of a vertebral
