220 THE BATH OOLITE PERIOD. CHAP. 



were made known by geological research, these were the most 

 extraordinary; and could they be now seen alive would appear 

 anomalies, if not monsters, in nature. 



The group of pterosaurians includes more than the three best 

 known genera, entitled dimorphodon, rhamphorhynchus, and ptero- 

 dactylus ; the first being found in the lias, the next not infrequent 

 at some places in the oolites, the third abundant at particular 

 localities in the cretaceous strata. Of these only rhamphorhynchus 

 is known in the oolitic district round Oxford, and it is found 

 almost only at and near Stonesfield; the exception being at St. 

 Clement's, in the Oxford clay, as will be noted hereafter. 



The title of Pterodactylus Bucklandi has commonly been given 

 to these remains, by authority of Goldfuss ; but Dr. Buekland 

 did not specially describe the bones of which he had mainly been 

 the discoverer, though his sagacious observation was fully employed 

 on the older liassic forms now called dimorphodon. Nor was the 

 want supplied by any naturalist till, in 1859, Professor Huxley 

 prepared descriptions and figures of most of the various fragments 

 which had been obtained, chiefly from Stonesfield, by different 

 collectors h . 



The Oxford collection contains specimens of most of the bones 

 required for a full understanding of the skeleton of rhampho- 

 rhynchus, but the exceptions, if few, are very important. We have 

 no fragments even of the cranium or of the upper or lower jaw. 

 A fine specimen, the anterior portion of the lower jaw, was ob- 

 tained not from Stonesfield, but from a quarry at Sarsden, called 

 Smith's Quarry, in strata of the Stonesfield series. It is in the 

 possession of Earl Ducie. Three other specimens of the lower 

 jaw have been seen : one was brought from Stonesfield by Mr. 

 Beckles in 1860; another is in the British Museum; a third 

 was in the private collection of Professor Quekett. We are with- 

 out trace, at Stonesfield, of the sternum, dorsal or caudal vertebrae ; 

 and no bone has been found to indicate the pelvic arrangement. 



These defects can be to some extent remedied by help of the 

 skeletons of dimorphodon in the lias, and pterodactylus in the 

 cretaceous rocks ; for other parts of the bony fabric we have con- 

 siderable if not complete materials of study. 



h Proceedings of the Geol. Soc., vol. xv. p. 658. 



