158 Reviews—Prof. Prestwich’s Geology, Vol. II. 
Il.—Diz Garrune Saurodon, Hays. By Prof. Dr. W. Dames. 
Ibid. pp. T2—78. 
URING the investigation of the teeth of Titanichthys, Dr. Dames 
D was led to study the semi-barbed teeth from the Huropean Chalk 
originally referred by Agassiz to the American genus and species 
Saurodon Leanus, Hays. The result is an interesting resumé of the 
varied fate of the fossils in question at the hands of different palee- 
ontologists. Their resemblance to the teeth of the Trichiuride is dis- 
cussed, and full references are given to the several descriptions and 
fizures. It is unfortunate, however, that Hays’ original memoir has 
not been consulted, nor yet the most important contributions of 
Leidy (Trans. Amer. Phil. Soc. vol. xi.) and E. T. Newton (Quart. 
Journ. Geol. Soc. vol. xxxiv.). The latter authors have shown that 
the European fossils are certainly not referable to Saurocephalus (of 
which Saurodon is a synonym), and those from the English Chalk 
are named Cimolichthys levesiensis. A. 8. W. 
aS a We IG eH Wass 
I.—Geronocy, Curmican, PuysicaL, AND STRATIGRAPHICAL. By 
JosepH Prestwicu, M.A., F.R.S., F.G.8. In T’'wo Volumes. 
Vol. I]. SrratiGRaPHicaL AND PuysicaL. Royal 8vo. pp. xxviii. 
and 606, with Geological Map of Europe, and numerous I1lustra- 
tions. (Oxford, at the Clarendon Press, 1888.) 
F the number of geological papers published every year in 
various parts of the globe were taken as a measure of the 
increase of our knowledge, our sentiments on the subject might fitly 
find utterance in the word “ Prodigious!” Nevertheless, while this 
great “talus heap of geological literature,” as it has been rather 
irreverently termed, may at times produce a feeling of dismay and 
oppression, yet we may derive comfort from the thought that in due 
course of time the leading facts and the general results of this mass 
of information are tabulated and expounded in the larger Text-Books 
and Manuals. 
Our advances in geological knowledge are then best gauged by 
such works as the one now before us, written as it is by one of our 
geological leaders, and whose object it is to exhibit the present state 
of the science. It might indeed be maintained that we are already 
well supplied with Manuals of Geology—Physical, Stratigraphical, 
and Paleontological; but it may also fairly be urged that one 
individual might devote his whole time to the literature past and 
present, and never learn a tithe of all that has been done in geology. 
Consequently the deficiencies of one work are compensated by others: 
and while we give honoured places on our bookshelves to the general 
Manuals of the older geologists—to Buckland, Bakewell, Trimmer, 
De la Beche, Phillips, Lyell, and Jukes, the value of whose works 
is now to a large extent historical; so alongside of Geikie, Green, 
Seeley, and Etheridge, we accord a hearty welcome to the two hand- 
some volumes by the ex-Professor of Geology at Oxford. 
