430 Reviews— Yorkshire Type Ammonites. 
In the sixth article, by Dr. A. Strahan, ‘‘South Wales” is dealt 
with, mainly so far as the region has been visited by the Geologists’ 
Association. Thus the oldest rocks described are the Silurian near 
Cardiff and in Gower. Attention is directed mainly to the Old Red 
Sandstone and Carboniferous rocks, the Trias and Lias, the Raised 
Beach and Caves of Gower, and the Glacial and post-Glacial deposits, 
concerning all of which is given a summary of the latest information, 
much of it acquired by the author during the progress of the 
geological survey. The intimate connexion between the Rheetic 
beds and underlying Keuper Marls, manifest from the stratigraphic 
and paleontological evidence noted by the author, is not, however, 
recognized by him, and his views differ from those of other writers in 
the Jubilee Volume (pp. 332, 491, and 863). In a final section on 
Physiography the author discusses the relations of the river-systems 
to the geological structure. 
The seventh and final article, on ‘“‘Cornwall, Devon, and West 
Somerset’’, is by Mr. W. A. E. Ussher, who has given accounts of 
a great series of formations from the most ancient rocks of the Lizard 
to the Pleistocene and Recent deposits. His table of strata and of 
igneous rocks, indeed, extends over more than two pages, and his task 
of summarizing the information on this varied series must have been 
an exceedingly difficult labour of love. 
The igneous rocks and the China clay are first dealt with; then 
follows an account of the Lizard from the pen of Dr. J. 8. Flett, who 
gives some of the results of his recent investigations on this complex 
group of mica-schists, quartzites, granulites, hornblende-schists, 
serpentine, gabbro, dolerite, and granite. The various schists of 
Start, Bolt, and Prawle are next described, and the author takes 
a ‘“non-committal attitude” regarding their age. The results of 
recent work on the small areas of Ordovician and Silurian and on the 
Devonian and Carboniferous rocks form the most important portion 
of the author's article. As he intimates, a good deal remains to be 
done before the grouping and relationship of all the divisions of 
Devonian and Carboniferous are determined. While he hesitates to 
accept Hicks’s view of the age of the Morte Slates, as the field-evidence 
does not favour the intercalation of Lower Devonian in the area where 
the Morte fossils were found, yet, as he remarks, ‘‘ detailed mapping 
on the six-inch scale may vindicate Hicks’s view.” 
The New Red Rocks and later deposits are described, some very 
briefly, but with special reference to recent researches. 
IV.—Yorxsuire Type Ammonites. Edited by S. 8. Bucxmay, F.G.S. 
Parts I and II, pp. i-xvi, with 24 plates and descriptions. London: William 
Wesley and Son, 1909 and 1910. Price per part 3s. 3d. net. 
f|\HE object of the present work is to give descriptions and illustra- 
tions of the Jurassic Ammonites that were named by Young & 
Bird and by Martin Simpson. It is remarked that the type-specimens 
of which sketches without descriptions were published by John Phillips 
are lost; but the majority of the specimens described and illustrated 
by Young & Bird, and those described (but not figured) by Simpson, 
