Page:Memoirs of the Geological Survey of Great Britain, Volume 1.djvu/405

392 2. Of living British species usually regarded as Northern, but not observed hitherto in glacial beds.

3. Of living British species not found fossil in typical glacial beds, but occurring in contemporaneous Italian newer pliocene strata.

4. Of species not now known in the British Seas, but still living in the Mediterranean. Not fossil in drift beds elsewhere.

5. Of glacial species of Arctic origin; with the exception of the first, not now living in, or doubtful inhabitants of, the British Seas.

6. Of extinct crag forms, those marked with an asterisk, are new species of Mr. Wood.

From the beds at Bridlington, Mr. Lyell enumerates 35 species of testacea, of which 20 were living forms, and 26 species common to the mammaliferous or Norwich crag. I have had an opportunity of examining a collection from this locality belonging to my friend Mr. Bowerbank, who, with his accustomed liberality, has permitted me to make use of it. It includes 28 species. Of these, Dentalium entalis, Aporrhais pespelicani, Littorina littorea, Turritella terebra, Buccinum undatum, Anomia ephippium?, Saxicava rugosa, Astarte compressa, Tellina solidula, Pleurotoma turricula, and Balanus balanoides, are common living British species known also as fossils in most glacial beds.

Trichotropis borealis, Natica groenlandica, Fusus Sabini and Astarte borealis, are rare North British species of Arctic origin.

Fusus fornicatus and scalariformis, Tellina groenlandica, are Arctic and Boreal American species, the first extremely rare, the others not now living in the British Seas.