The expense of printing this volume has been defrayed out of the Funds of the Syndics of the University Press; and Professor Sedgwick hereby expresses his grateful thanks to them for this great favour.
PREFACE.
This memoir is a portion of the Catalogue of the Woodwardian Museum which has been made at Professor Sedgwick's request and at his cost. When the Professor laid upon me his commands to prepare a Catalogue of the Museum, it was planned in three distinct works. First, a series of indexes to the specimens in the great divisions into which the Museum is arranged; secondly, a series of memoirs upon the orders and classes of animals concerning which new knowledge is given by fossils in the Museum; and, thirdly, memoirs descriptive of those species contained in the arranged collections which are at present unknown in scientific writings.
For the convenience of students the Catalogue is made in parts. The Syndics of the University Press printed last autumn as an example of the "Indexes to the Museum," an Index to the Pterodactyles, Birds, and Reptiles from the Secondary Strata. And this memoir is an example of the second kind of Catalogue, which explains the structures of the Pterodactyles of the Cambridge Greensand. In its progress questions have arisen which necessitated an examination both of the method, of research in comparative anatomy and of its results in classification. And in so far as the views here advanced differ from those commonly taught, the discrepancy is due to the writer's imperfect faith in the results of the inductive method of research, as commonly used by modern writers on Palæontology. It has not been consistent with the plan of this little work to do more than scatter through it a few hints upon method, a subject which will more fitly be discussed with a part of the Catalogue which forms a synopsis of the osteology of the fossil animals usually named Reptiles. The views here urged have however but little of novelty. The name Ornithosauria was proposed by the distinguished naturalist Prince Charles Bonaparte in 1838. The group as an order was recognized by Von Meyer in 1830. The affinities of the brain appear to have been detected by Oken, and the bird-like character of the respiratory system was expounded by Von Meyer. And most of whatever this memoir contains has been already thought or discovered by the German philosophers, who have had the Pterodactyles as fossils of their fatherland, though my own conclusions were arrived at separately and from different materials.
The oldest Ornithosaurians are from the Muschelkalk of Germany. In England the oldest are from the Lias,—several species of Dimorphodon—a genus in some respects nearly resembling the Pterosaurians of the Cambridge Upper Greensand. In the Oolite of Stonesfield are several species of Rhamphorhynchus or a similar genus. The great Pælolithic period from the Oxford Clay to the Kimeridge Clay, has yielded in its several divisions small Pterodactyles of new species. And the Psammolithic period from the Portland Sand to the Lower Greensand has afforded many excellent remains both of true Pterosaurians in the Purbeck, Wealden, and Potton Sands, and of animals which indicate a new order of Ornithosauria having affinities with Von Meyer's thick footed saurians, the Dinosauria. In the Cretaceous series, Galt, Upper Greensand, and Chalk all have representatives of the Pterosauria; but no English stratum has hitherto yielded so many as the Cambridge Upper Greensand. From this formation the collection accumulated during Prof. Sedgwick's long professoriate is unequalled; though, excepting a few fine bones from the Chalk and the Purbeck Limestone, the Woodwardian Museum is as yet deficient in Ornithosaurians from the other Secondary Rocks. Until descriptions of these animals shall have been published a classification of the Ornithosauria must necessarily be provisional. And it cannot be expected that descriptions of the structure of Cretaceous Pterosaurians here given will hold good for all the Ornithosaurian sub-class.
Finally, I have gratefully to express my thanks to the many friends, English and German, who have aided me with specimens and with their writings; to the chiefs and officers of the English museums, especially Prof. Owen, Prof Humphry, Prof Newton, Prof Phillips, Prof Flower, and Prof. Huxley; to the officers of the University Library, especially Mr Bradshaw, and Mr Crotch, for aid in consulting books; but chiefly to Prof Sedgwick, who while employing me as his paid Assistant to aid him in his Museum work, has generously encouraged me to carry on for several years, without restraint and as part of my daily labour, an investigation of which this treatise is the first fruit. Prof. Sedgwick has placed at my disposal an ample number of copies for distribution among those who take an interest in the Museum; and especially among those who have contributed to the Ornithosaurian collections, and aided me in my work.
January 3, 1870.