Page:Quarterly Journal of the Geological Society of London, vol. 27.djvu/245

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PRESTWICH—CRAG-BEDS OF SUFFOLK AND NORFOLK.
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ever, have an equally wide range in a southern direction, and the other 4 are entirely southern in their range. Owing to the way in which so many Cirripedes attach themselves to floating seaweed, wood, shells, Crustacea, and Bryozoa, their range is generally wide, and they have less definite value in a geological point of view. Mr. Darwin states that Pyrgoma anglica is found from 12 to 45 fathoms, and the Verruca Stromia at all depths from low water to 90 fathoms.

Corals.—M. Milne-Edwards could only recognize 3 species of Corals in the Coralline Crag, and considered them all to be extinct species,—one, the Cryptangia Woodii of the lower Crag zones, belonging to an extinct genus. Professor Duncan, however, informs me that in the last expedition of H.M. ship 'Porcupine,' specimens of a Coral were found alive in Tangier Bay, which could only be regarded as a variety of the Sphenotrochus intermedius described by Von Munster. The habitat of that species is between 60 and 300 feet. Professor Duncan also says that the deep-sea dredgings off the south-west coast of Spain in the same expedition of the 'Porcupine ' have yielded a Flabellum which, although not very closely allied to the Crag form (F. Woodii), is found in the Miocene deposits of the south of Spain. This species exists on the sea-bed at a depth of from 1824 to 5964 feet, and therefore it is reasonable to assert that Flabellum Woodii was a deep-sea form. It is more closely allied to Indian species than to those of more northern seas, viz. Flabellum laciniatum, Ed. & H., and Flabellum MacAndrewi, Ed. & H. Prof. Duncan further remarks that these genera are such as chiefly inhabit deep water, and that neither they nor their congeners have ever formed part of the assemblage which produces reefs.

Echinodermata.—16 species have been found in the Coralline Crag, of which only 3 are recent species—2 British and Scandinavian, and 1 Mediterranean. If we were to judge by genera alone, several of the Crag genera are such as are now found only in warm and tropical seas. Their range of depth is variable. The Comatuloe generally inhabit deepish water. Different species of Echini seem to mark the different zones of the Crag.

Foraminifera.—One hundred and five species (including notable varieties) have been recorded[1] by Messrs. Rupert Jones, W. K. Parker, and H. B. Brady. Of these, 5 possibly are derived from other strata; 53 are living species, and 47 are extinct. Of the recent species, 37 are stated by the authors to be living in the North Atlantic and 37 in the Arctic seas. The species of the Foraminifera from one bed of Crag at Sutton, they observe, "are remarkable, for the most part, for size and abundance. The leading forms are Miliola, Lagena, Nodosarina, Polymorphina, Textularia, Planorbulina, Pulvinulina, and Nonionina. As a fauna, they are best represented (in our collections) by dredgings from the Atlantic, south of the Scilly Isles, at from 50 to 70 fathoms, and from the Mediterranean north of Sicily at 21 fathoms. From all

  1. "Monogr. Foram. Crag" (Pal. Soc), part 1, 1866; and "Monogr. Polymorphina" (Linn. Soc), 1870.