Page:Quarterly Journal of the Geological Society of London, vol. 27.djvu/244

130 to the Coralline Crag. Of the species and genera of Bryozoa inhabiting shallow water, there is a marked absence.

The Bryozoa make their appearance in the lowest bed of the Coralline Crag. I found species of Cellepora and Eschara amongst phosphatic nodules at the base of this deposit. At Ramsholt the Cupularia denticulata, C. canariensis, and other species were met with. In ascending order they become gradually more numerous, and in zone "e" they attain a large development and, further, occur in the position and place of growth. The species seem somewhat gregarious. At Sutton we find chiefly species of Cellepora and Eschara in this bed, whilst at Broom Hill little else is found but the various species of Fascicularia and Alveolaria and some Cellepora. In the highest bed, "f," of this division, where extremely fine sedimentary seams are intercalated with a mass of comminuted shells, the delicate Salicornaria sinuosa seems to have flourished.

The upper division of the Coralline Crag, as is well known, is composed to a great extent of fragments of Bryozoa and comminuted shells, with a certain number of entire Alveolarioe and Fascicularioe and shells. As the structure of these beds shows them to have been subjected to the action of shifting currents and frequent reconstruction, it is probable that these banks of Bryozoan remains and dead shells were formed in great part by the scour of deep-sea currents out of the upper beds of the lower division of the Coralline Crag. At the same time, the perfect state of the Alveolarioe and Fascicularioe and the known habits of most of the Bryozoa render it perfectly possible that many of the individuals may have lived among these shifting currents and shell-banks.

Crustacea.—Besides the specimen referred to Gonoplax angulata, Mr. Woodward has ascertained the existence in the Coralline Crag of the following species:—Cancer pagurus, Carcinus moenas, Maia squinado, and Portunus puber and depurator.

Entomostraca.—Mr. Rupert Jones describes 18 species of Entomostraca from the Coralline Crag*, 3 only of which are known for certain as living forms (Cythere punctata, C. ceratopora, and Loxoconcha tamarindus), all in the Atlantic—though Cythere laqueata, C. sublacunosa, C. trachypora, and C. retifastigata have almost undistinguishable allies in the Norwegian sea; and the subdeltoidal Bairdia of the Crag has its closest analogue (B. fusca, Brady) in the Australian seas. The last-mentioned seems to be of deep-water habits; but the others are mostly littoral.

As we do not know the exact distribution of the Entomostraca in the Coralline Crag, we cannot speak of them in relation to the different zones.

Cirripedes.—Mr. Darwin has described 10 species in the Coralline Crag, 4 of which are from Ramsholt and 6 from Sutton. The proportion of recent to extinct species is 6 to 4. Of these six, four are species still living in the British seas, one ranging to the Scandinavian coast and one to the Arctic seas. Both these species, how-

Tertiary Entomostraca in 1870 (Geol. Mag. vol. vii. pp. 155-159).
 * These conclusions are drawn from Prof. Rupert Jones's revision of these