512 



lions, tigers, hyaenas, and other beasts of prey which inhabited the 

 country at the same period. 



The remains of at least two distinct Saurian animals have been 

 discovered by Dr. Riley and Mr. Samuel Stutchbury, in the dolo- 

 mitic conglomerate of Durdham Down near Bristol. They are 

 allied to the Iguana and Monitor, but the teeth, vertebrae, and other 

 bones exhibit characters by which they are seen to be generically 

 distinct from all existing reptiles. They are particularly deserving 

 of your attention as occurring in the bottom of the magnesian lime- 

 stone formation, the oldest strata in which the bones of reptiles have 

 as yet been found in Great Britain. The most ancient examples 

 of fossil reptiles known on the continent of Europe occur also in 

 the zechstein of Germany, a formation of about the same age. 



I alluded last year to a memoir of Sir Philip Egerton's, in which 

 he pointed out some peculiarities in the structure of the cervical 

 vertebrae of the Ichthyosaurus. He has now proved that in all the 

 species of this genus there are three accessory bones,which he pro- 

 poses to call, from their shape and position, subvertebral wedge 

 bones. They are supplementary to the atlas, axis, and third ver- 

 tebra of the neck, and seem to have escaped the observation of 

 Cuvier and other osteologists. 



Mr. Lewis Hunton has communicated to the Society an elaborate 

 account of a section of the upper lias and marlstone in Yorkshire, 

 showing that different beds in those formations are characterized 

 by particular species of Ammonites and other Testacea, each species 

 having a limited vertical range. His observations are valuable not 

 only as illustrating the distribution of fossils on the coast near 

 Whitby, but also as furnishing a point of comparison between that 

 district and many others in Great Britain. Mr. W. C. Williamson 

 of Manchester has had the same object in view in studying the fos- 

 sils of the oolitic formations of the coast of Yorkshire, and informs 

 us, as the result of his patient investigation, that although certain as- 

 semblages of fossils abound in particular subdivisions of the oolite, 

 many species range from the lowermost to nearly the highest beds. 

 This inference is confirmed when we compare the lists drawn up 

 by Mr. Williamson, and those published by Professor Phillips and 

 other competent authorities. Thus some of the shells of the in- 

 ferior oolite, mentioned in Mr. Williamson's list {Trigonia gibbosa,. 



