116 SUPPLEMENT TO GREAT OOLITE MOLLUSC A. 



contents are detailed with all the care and precision that might be expected from a person who had been 

 long resident in the locality. Within the few years following appeared the elaborate works of Goldfuss, 

 Ziethen, Roemer, Dunker, Agassiz, Deshayes, Sir R. Murchison's second edition of the ' Geology of Chel- 

 tenham,' the ' Catalogue' of Professor Morris, the memoir of D'Archiac on the Aisne, several memoirs by M. 

 Eudes Deslongchamps on the fossils of the Oolites of Normandy, a portion of the ' Paleontologie rran9aise' 

 of D'Orbigny, Quenstedt's ' Wurtemburg,' and the 'Lethea' of Bronn. These works, together with others 

 which bear less directly upon the subject of the Lower Oolites, tended very materially to extend and correct 

 the knowledge of their fossils. During the same period also the fossils of the Great Oolite in Gloucester- 

 shire had become extensively dispersed, and were compared with those from the Yorkshire coast, collected 

 and distributed with great perseverance by Mr. Bean during a lengthened period. The first published 

 results of influences so potential appeared in 1850, when M. d'Orbigny, in his ' Prodrome de Paleontologie,' 

 placed many of the so-called Great Oolite Yorkshire fossils in his Etage Bajocien, or Inferior Oolite. In 

 the same year appeared the first part of the monograph on the Great Oolite MoUusca, in the introductory 

 remarks to which the authors pointed out the afiinity of the Yorkshire so-called Great Oolite fauna to that 

 of the Inferior Oolite, and, as a measure of precaution, were careful to keep the doubtful Yorkshire fossils 

 distinct, both in plates and descriptions, from the Great Oolite fossils of the south of England. The various 

 works and lesser memoirs upon the Lower Jurassic rocks published between 1850 and the present time 

 would of themselves constitute a considerable list. Without enumerating them, it will be sufiicient to 

 mention that, in 1856-8, Dr. Albert Oppel, in his remarkable work, ' Juraforniation,' placed the Yorkshire 

 Phytiferous beds with the Inferior Oolite, and considered that they did not even represent the highest stage 

 of that formation. In 1857 the present writer expressed, in a little work, 'The Cotteswold Hills,' convic- 

 tions of similar import. In 1859 Dr. Wright enforced similar views, accompanied by extensive details and 

 lists of Inferior Oolite fossils, in a contribution to the ' Journal of the Geological Society.' The previous 

 Great Oolite Monograph contains four plates of these Yorkshire intercalated marine Testacea ; some of 

 which, however, pass upwards into the Great Oolite of the Cotteswolds and into the Cornbrash, as will be 

 ascertained from the descriptions. In excluding them from the present Supplementary Monograph, the 

 writer begs to state that he consented to their admission into the former work with great reluctance, in 

 deference to the opinion then prevalent that they pertained to the Great Oolite, but with a strong impression 

 (formed in 1839, upon perusing the memoir of Professor Williamson) that they constituted an Inferior 

 Oolite fauna. 



The Palaeontologists of France, in their expositions of the Great Oolite fossils of that country, have, 

 within the last few years, fully proved, by the general identity and association of species, that the fauna of 

 the Minchinhampton beds is not exceptional or local merely, as some have supposed, but represents a very 

 ample and characteristic series of Mollusca, a large number of which are also found in other and distant 

 localities at the same geological horizon. Other not less interesting and important facts, confirmatory of 

 this view, have recently been afforded by researches in English strata of the same epoch. The Oxfordshire 

 railway sections of the Great Oolite and Forest Marble have yielded to Mr. Whiteaves a varied series of 

 Testacea, a list of which he has kindly communicated to nie, together with many of the fossils, inchuliug 

 those which are not known in the Minchinhampton beds ; the result is, that of 122 Great Oolite and 48 

 Forest Marble shells, in all 140 species, obtained by that gentleman in the Oxfordshire beds, upwards of 

 114 are also common to the Minchinhampton beds. An extensive series of Forest Marble shells from 

 the clay beds of Wiltshire, Somersetshire, and Dorsetshire, liberally placed at my disposal by Mr. Walton, 

 has produced a larger number of novel forms, as might have been expected from the very different litho- 

 logical conditions of the deposit ; nevertheless there is still a majority of Minchinhampton shells, and the 

 entire assemblage is even more remotely allied to the Yorkshire fauna than is that of Minchinhampton. 

 The general discordance, therefore, of the Y^orkshire and southern faunas of the supposed Great Oolite 

 within so small an area as England would lead us to infer their separation chronologically, even if we were 

 unable to assign the northern series to that of an older and well-known era. 



