Bibliographical Notices. 61 
leigh Salterton, Devonshire.” By the Rev. P. B. Brodie, M.A., 
The author notices some previous remarks upon these pebbles, 
which, in Warwickshire and elsewhere, either occur in the Trias or 
have been derived from it. To account for these, he supposed that 
there had been a more northerly extension of Silurian rocks than 
can now be detected in Central England. The Lickey quartzite has 
been supposed to have contributed some of these; but the author 
states that he has not found any one well-detined Llandovery species, 
but that the most characteristic are Lower Silurian. These pebbles 
are most abundant south of Birmingham, towards Warwick and 
Stratford-on-Avon. They agree lithologically with the Budleigh- 
Salterton pebbles; these, as it has been shown, are partly Lower » 
Silurian, partly Devonian, partly Carboniferous. The author gives 
a list of species collected by him from the Warwickshire pebbles. 
Sixteen are present from the twenty-four Lower-Silurian forms 
found in Devonshire. Notwithstanding their identity, physical 
considerations forbid the supposition that they have been derived 
directly from that locality or Normandy ; so that it is probable these 
Lower Silurian quartzite rocks once extended much further to the 
north. 
BIBLIOGRAPHICAL NOTICES. 
On the Structure and Affinities of the Genus Monticulipora and its 
Subgenera. By H. Aturyne Nicuorson, M.D., D.Sc., F.R.S.E., 
F.LS., Professor of Natural History in the University of St. An- 
drews. 8vo. Edinburgh & London: W. Blackwood & Sons, 1881. 
Tus work is a further result of the continued paleontological re- 
searches of Prof. Nicholson, and although perhaps not so generally 
interesting as his previous volume on the Tabulate Corals, is not a 
less important contribution to the history of a difficult and variable 
group of Ccelenterata—the Monticuliporide, whose relations and 
affinities have of late years been the subject of investigation. In 
his previous work Prof. Nicholson only treated generally of Monti- 
culipora and its immediate allies. The matter there given, greatly 
expanded and improved by more extended observations of his own 
and other authors’, is incorporated in the present treatise. 
The general history and literature of Monticulipora and the allied 
genera, including an analysis of the classification of Dybowski, is 
followed by a chapter on its comparative structure, in which the 
forms of the corallum, the differential structure of the walls of 
the corallites as compared with those in Stenopora and Cheetetes, 
and the surface features are described; under the latter head are 
the “‘ monticules ” (circumscribed areas on the surface of the coral- 
lum, which are more or less ¢levated above the general level), from 
the presence of which the name of the genus is derived. 
