Reviews—Prof. Kayser’s Text-book of Geology. ool 
extended as in Dicynodonts, and conforms to the type of Phocosaurus, 
which is regarded as Theriodont. The pubis and ischium are united 
together on the Dicynodont plan, but are only moderately developed. 
The scapular arch is completely known, and is formed of scapula, 
-eoracoid, and pre-coracoid, as in Dicynodon and Pareiasaurus. The 
humerus and bones of the fore limb were relatively short, and only 
fragments have been preserved which appear to be referable to ulna 
-and radius. 
The hind limb is known from several examples of the femur, 
which resembles that of Pareiasaurus in the proximal end, but at the 
distal end is more like the type described as Saurodesmus. 
The tibia is known from its proximal and distal ends; it has a 
general resemblance to that of Pareiasaurus, but is more slender. 
These types are regarded as constituting a distinct group, named 
Deuterosauria, which is in many respects intermediate between the 
Placodontia and Theriodontia, but in skull structure appears also to 
approach Nothosaurs and Plesiosaurs. 
a53 22H We SE Jah WAYS 
I.—Text-Booxk or Comparative Grotocy. By HE. Kaysrr, Ph.D. 
Professor of Geology in the University of Marburg. Translated 
and Edited by Paine Laks, M.A., F.G.S., late Harkness Scholar 
in the University of Cambridge. 8vo. pp. 426, with 596 Illus- 
trations, 73 Plates and 70 Figures in the Text. (london: Swan, 
Sonnenschein & Co., 1893.) 
ies undertaking the translation of Dr. Kayser’s “Lehrbuch der 
geologischen Formationskunde” Mr. Philip Lake has done 
‘more than preparing a mere translation. Dr. Kayser’s work was 
intended primarily for use in Germany, it has therefore been found 
desirable, in the present edition, to very considerably enlarge those 
portions of the work which deal with descriptions of extra-German 
-countries. Mr. Lake has taken the advice of several of his geological 
colleagues, whose assistance he duly acknowledges, and amongst 
other modifications he has introduced the divisions Cambrian, 
Ordovician, and Silurian, instead of the older subdivisions into 
‘Cambrian and Silurian only. 
In the introduction the author gives a history of the names which 
have been adopted in this country and in Germany for the great series 
of stratified deposits, and the various subdivisions now generally 
recognised by geologists both at home and abroad. 
Division I treats of the general characters and composition of the 
Archean rocks, illustrated by ten sections. The total thickness of 
the Archzan in North America has been estimated at 50,000 feet, 
-and in Bohemia at 100,000. 
In II the Paleozoic or primary group is considered, comprising 
‘the Cambrian, Ordovician, Silurian, Devonian, Carboniferous and 
Permian, the six systems forming together a succession of beds fully 
100,000 feet thick. 
