PRESTWICH — CRAG-BEDS OF SUFFOLK AND NORFOLK. 



349 



While, therefore, all agree in considering the mammalian remains 

 generally to be extraneous fossils, there is a difference of opinion, 

 but not a great one, with respect to their age and origin. Some 

 small portion of these fossils are doubtless of the age of the Red 

 Crag. Unlike the great proportion of the Mammalian and Ceta- 

 cean remains, which possess so peculiar a fossilization, are so dense 

 and so worn that they show at once their extraneous origin, some of 

 the large Whale-vertebrse and some of the small fish-vertebrse are 

 so little mineralized and worn that they cannot be considered de- 

 rived fossils*. At the same time the very circumstance that a 

 portion of the Cetacean remains are, like the land Mammalian re- 

 mains, heavily mineralized and worn, makes one cautious how far 

 that mineralization and that wear should be construed as a proof of 

 extraneous origin. 



The discovery by Mr. Colchester (ante, p. 117), in the pit which 

 he opened at Sutton, of teeth of Mastodon, Rhinoceros, &c., with 

 Cetacean remains, all of the same species as those found in the Red 

 Crag, and, like the latter, in a shingle-bed at the very base of 

 the Coralline Crag, shows that some of these remains of the Red Crag 

 may have been derived directly from the Coralline Crag, although 

 they may have to be carried yet further back in the geological series f; 

 while I consider it probable that some will be found to be of the 

 age of the Coralline Crag itself. 



Mr. Darwin describes J eight species of Cirripedia from the 

 Red Crag, of which six are living and two supposed to be extinct. 



Edward Forbes § described six species of Echinoderms, one of 

 which only he identified with a living species ; but one is proba- 

 bly derived from the Coralline Crag ; Echinocyamus suffolcensis is 

 probably only a variety of the E. pusillus ; and Echinus Henslowii 

 he thought might be related to an undescribed species from Iceland. 

 This would give one extinct to three living species. 



Land. 

 Tapirus priscus, Kaup. 

 Ursus arvernensis, Cr. tf- Job. 

 Megaceros hibernicus ? 



To these I would add 

 Eleplias (meridionalis ?). 



Mauine. 

 Lamna. 

 Otodus. 

 Phoc£ena. 



Squalodon (antverpiensis?). 

 Trichecodon Huxleyi, Lank. 

 Ziphius angulatus, Ow. 



angustatus, Ow. 



compressus, Ow. 



gibbus, Ow. 



inedilineatus, Ow. 



planus, Ow. 



tenuirostris, Ow. 



* The finest series of the extraneous fossils of Eed Crag I know of is that form- 

 ing part of the valuable collection of Red-Crag fossils in the possession of Mr. 

 Whincopp, of Woodbridge, who has devoted much time and care to secure the 

 many rare specimens brought to light by the Coprolite-diggings which for the 

 last few years have been carried on so actively in the neighbourhood of Sutton 

 and Woodbridge. 



t In the same way it is probable that the dark sandstone nodules, with casts 

 and impressions of shells, so common in the Red Crag at Bawdsey, Sutton, 

 &c.,may have been derived indirectly through the Coralline Crag. 



% Pal. Soc. 1854. % Ibid. 1852. 



