474 Reviews—R. H. Rastall’s Agricultural Geology. 
of 1847 should be accepted; lastly, Bolten’s Zwurrzs of 1798 has 
priority of Plewrotoma, of Lamarck, of 1799. Few systematic works 
on paleontology are entirely free from blemishes connected with 
nomenclature, and it is only by persistently calling attention to them 
that we may hope to guard against similar errors in the future. This 
criticism, therefore, is offered in no captious spirit, being considered ~ 
to detract in no way from the great excellence of the work which, 
when completed, will rank as a valuable guide and reference book to 
the history of the later Tertiary Mollusca of this country. Special 
mention should be made of the beautiful photographic figures prepared 
by Mr. J. Green, which form the plates that adorn the monograph. 
Not only are the British Crag shells figured in this way, but illustra- 
tions are frequently given side by side of recent and foreign specimens 
for purposes of comparison. Thus, the author attains an accuraey in 
his determinations which will be of inestimable importance, not only 
to the paleontologist but also to the collector, who will almost be 
able to name his shells without reference to the text. 
The work appears to be a long way from completion, but we 
earnestly trust that, when the last part is in preparation, the author 
will provide us with an ample index so that every specific and 
generic name used, whether in synonymy or elsewhere, shall be 
brought out alphabetically. With such an adjunct the utility of 
this valuable memoir will be very greatly enhanced. 
ITI.—Acricutrurat Grotocy. By R. H. Rasrarz, M.A. 8yo; 
pp. x + 332. Cambridge University Press, 1916. 
[]\HE place occupied by geology in an agricultural curriculum varies 
so much in different universities and other institutions that the 
task of writing a suitable textbook is a peculiarly difficult matter, 
and we welcome this conspicuously successful attempt by so 
competent a geologist as Mr. Rastall to fill a gap that has long 
existed. About half the text is taken up by chapters on Minerals 
and Rocks, Weathering, Transport and Corrasion, Sediments, 
Superficial Deposits, and Soils, including most of those matters that 
are of primary importance from an agricultural point of view. These 
are models of their kind, as might be expected from one of our leading 
petrologists. The literature on soils is so scattered, and so little has . 
been attempted in this country by way of soil surveys, that all those 
concerned with scientific agriculture are indebted to the author for 
his able correlation of the chief available facts. He regrets in his 
preface that considerations of space have prevented the inclusion of 
full details on the subject of mechanical soil analysis, but we hope 
these will find a place in the next edition, though of course aware 
that they have been ably treated by Mr. A. D. Hallin his well-known 
works. The essential facts of water supply and drainage are 
clearly set forth in chapter vii, the page on ‘‘dew ponds’? being of 
particular interest. Then follows a chapter on geological maps and 
sections, which would be much improved by a few cuts to illustrate 
the chief kinds of map in common use. The rest of the book is 
mostly occupied by well-balanced chapters on stratigraphy, the one 
