120 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



(e) The artist had so badly represented the figure of the French species, 

 that it was not until the specimens were compared that the mistake 

 of naming it anew could be discovered. 

 (/) This shell is here in too imperfect a state to admit of a positive deter- 

 mination. 

 (^r) There are two French species, the Dreissena antiqua, Mell., and Mo- 

 diola ungulans, Desh., which require comparison with this. They 

 are both fovmd in the " Sables Interieurs," but I have not met with 

 them ; and although the figures and descriptions do not quite agree, I 

 suspect a closer resemblance than is apparent. 

 [h) The P. terebratularis is a very variable shell. M. Deshayes has in his 

 " Coquilles Fossiles " quoted it from Braeheux and from Etampes, but 

 has since restricted it to the former locality, and therefore to the 

 " Lower Tertiaries." This species apparently includes the P. Plum- 

 steadiensis and P. brevirostris of Sowerby. 

 (i) This has been referred to the U. Solandri, but, as well as the crushed 

 and imperfect state of the specimen will allow us to judge, mcor- 

 rectly ; it rather closely resembles the French species which has lately 

 been figured by M. Watelet from the " Lignites " of the Soissonnais. 

 (_;') This, which is a very rare shell at Woolwich, is referred with a doubt to 

 a French species that it seems identical with, except that it is always 

 very much smaller. This, however, may arise from the more fresh- 

 water conditions at this locality. 

 (k) These species of Sowerby, although now considered only as one, form, 

 as do also his species of the Ostrea, well-marked varieties constant in 

 most cases to different beds of the Woolwich and Reading series, and 

 caused apparently by this difference of habitat. 

 (l) The Biicciiium ambiyuum, Desh., also resembles some varieties of this 

 shell, to which I have also referred the B. (jranulosiim with a doubt. 

 Having seen M. Deshayes' specimen of the Fusus deceptiis, I have 

 little hesitp.tion in identifying it with the Woolwich species. 

 {m) Sowerby gave originally four species of Fusus from Woolwich. Two 

 of these have snice been excluded, and upon comparing a large series 

 of these other two species, I cannot feel satisfied that even they are 

 distinct. The F. gradatus seems to me to be the young of the 

 F. latus. 

 («) Several veiy small univalves are figured by Deshayes and Melleville 

 from the Lower Tertiaries of France. I cannot quite identify any of 

 them with the Woolwich species, although I suspect that some of them, 

 especially the Melania tritacea, Desh., and the Paludina mUiola and 

 intermedia, Mell., may prove to be the same. From the figures of 

 Deshayes, the Woolwich species, however, seem to have a closer re- 

 semblance to some specimens from the Calcaire Lacustre of St. Ouen 

 and ^lontmorency. 

 (o) M. Deshayes has specimens of this shell from the Lignites of the Sois- 

 sonnais, and it appears to resemble some of the Woolwich specimens. 

 It is difficult however to distinguish the species of this genus, and al- 

 though at Woolwich there seems at first sight to be two or three spe- 

 cies, it is doubtful whether they will not all prove vaiieties of the next 

 species. 

 {p) This is a very variable shell, the fusiform variety being the specimens 

 figured by Sowerby as the M.fusiformis. This latter must however, 

 I think, be confined to the fluvio-marine series of the Isle of Wight. 

 (q) This and the preceding species require comparison with the French spe- 

 cimens, as the figures given of them are not sufficiently distinct. 

 (r) It is doubtful whether this may not be a different species ; but in this. 



