071 the Identification of certain Loiioer Greensand Fossils. 445 



8th. The last fossil on the list is " A/npidlaria laevigata, 

 Desh.," which I had identified with the Littorina rotundata of 

 Sowerby, referring the shell to the genus Natica, Dr. Fitton 

 having taken his list from my unpublished catalogue of the 

 Lower Greensand fossils in the collection of the Geological 

 Society, adopted the revised name. Were French naturalists 

 in the habit of referring specific appellations to the original 

 authorities for them, and not of appending their own names 

 after those of old species, whenever they remove them from 

 one genus to another, M. Leymerie would probably have 

 searched a little more diligently for a figure and description of 

 this pretty shell, which is undoubtedly the Ampullaria Icsvi- 

 gata, as I am convinced from comparison of British with 

 French specimens. Moreover, the British shell was returned 

 from France with its French name. If M. Deshayes persists 

 in referring this species to Ampullaria instead of Natica, it is 

 through a perversity unworthy of the first conchologist of 

 France. Why he should refer a fossil abundant only in ma- 

 rine beds, associated only with species indicating a consider- 

 able depth of sea, and closely allied to several existing forms 

 of Natica, to a freshwater genus, such as Ampullaria, is to me 

 unaccountable, and would be so to M. Leymerie, were he na- 

 turalist enough to perceive the difficulty. 



So much tor the list of " especes contestees," on account of 

 my supposed errors in which, M. Leymerie afterwards ex- 

 presses a doubt about all my determinations. His example 

 in proof is an unfortunate one. With large suites of Gryphaa 

 sinuaia and G. leevigata before me, and after an examination 

 of numerous specimens of those shells in their native beds, I 

 came to the conclusion, that not only were they forms of one 

 species, but that Fxogyra aquilina and Exogyra Coidoni {sub- 

 sinuata, Leym.) were also only varieties of this changeable 

 shell. I came to this conclusion, jvith the original English 

 types before me, with specimens of the true Coulofii brought 

 from Neufchatel by Captain Ibbetson and named by M. Agas- 

 siz, specimens from the Crimea furnished by Mr. Murchison, 

 and an extensive series collected in the Neocomian beds of 

 France by Dr. Fitton and named by M. Cornueil. Such a 

 way of going to work scarcely warrants the charge of hasti- 

 ness. 1 feel confident that if M. Leymerie would honour us 

 with his presence at this side of the channel, and look at the 

 varieties of this Gryphcea, intermingled at Atherfield and else- 

 where, he would no more think of making many species out 

 of it, than of the far more distinct varieties of Ostraea edulis (a 

 case exactly parallel) displayed in a London oyster-cellar. 



As to the identity of Trig07iia caudata of Agassiz with the 



