Mr. S. Wood on the Extraneous Fossils of the Red Cray. 485 



under which he had lately found portions of the stem of this coral 

 traversing nodules in the London Clay of Highgate. The nodules 

 are of different sizes, and vary from a cylindrical to an ovoidal shape. 

 Mr. Wetherell having also observed unmistakeable fragments of the 

 same Graphularia holding the same relative position in nodules from 

 the Red Crag, differing from those of the London Clay only in having 

 been more rounded and polished by aqueous action, brought the 

 subject before the Society as a link in the chain of evidence of the 

 so-called " coprolitic " cJr " phosphatic " nodules of the Red Crag 

 having been to a great extent derived from the destruction of the 

 London Clay. The author also offered some observations on the 

 structure of other nodular bodies in the London Clay and in other 

 deposits. 



2. " On the Extraneous Fossils of the Red Crag." By S. V. 

 Wood, Esq., F.G.S. 



In pursuing his investigations as to the geologic age of the Crag, 

 the author found it necessary to decide as to what are the "derivative" 

 fossils which are mixed with the native fossils in this deposit. This 

 has been a matter of some difficulty. Mr. Wood enumerates the fol- 

 lowing genera that may have supplied species or specimens to the 

 Red Crag : — Chama, Cardtta, Astarte, Cyprina, Isocardia, Limopsis, 

 Turritella, Vermetus, Cancellaria, Terebra, Voluta, and Pyriila ; and he 

 observes that out of 240 species of moUusca found in the Red Crag, 

 and belonging truly to a modern tertiary period, forty, or perhaps 

 fifty, might be considered as derivative fossils, though possibly some 

 of them may have lived on from the period of the Lower to that of the 

 Upper or Red Crag. Some few extraneous fossils found in the Red 

 Crag appear to the author to have been casts of shells from some 

 freshwater deposit, probably of old tertiary date, but of which no 

 other trace has been recognized. Mr. Wood regards the relics of 

 terrestrial mammals found in tlie Red Crag as extraneous to that 

 deposit, as well as the Cetotolites or relics of whales. Remains of two 

 species of Hyracotherium, originally derived from the London Clay, 

 have occurred in this Crag ; also a tooth said to be of a Corypho- 

 don. The remains of Ursus, Canis, Vulpes, Felis, Trogontherium, 

 Mastodon, Rhinoceros, Eqmis, Sus, and Cervits have been derived 

 from some Upper Tertiary deposits ; but Mr. Wood is uncertain 

 whether the Crag relics of Hippotheriimi and Hyccnodon may not have 

 come from some Aliddle Tertiary beds. The remains of Balcenodon 

 certainly were not derived from the London Clay, as has been sug- 

 gested, but, with the Delphimis, have come from some tertiaries of a 

 later date. Crocodile, Turtle, and Snake remains, fossil wood, 

 crustaceans, and moUusca have come from the London Clay. Many 

 of the fish-remains are London Clay fossils ; but some have been 

 washed in from beds similar to those of Bracklesham ; and some, 

 including the teeth of Curchurodon mec/alodon, have a])parently been 

 derived from Middle Tertiary beds not existing now in this area. 

 Some Chalk fossils, and several fossils from the Middle Oolites, have 

 also been collected in the " phosphatic beds." Mr. Wood described 

 the relative proportions iji which the dilFercnt derivative fossils 



