200 
THE GEOLOGIST. 
Figures and Descriptions of the PalcBozoic Fossils of Corn- 
wall, Devon, and West Somerset, observed in the course of 
the Ordnance Geological survey of that district. By J* 
Phillips^ F.G.S. Longman^ and Co., 8vo. 
What we have said in the preceding Review with reference 
to the objects of general surveys, is apphcable in the present 
instance in so far as the work to which we now call attention, 
is a portion of a great undertaking of a similar nature, the 
details of which have been recorded by separate authors. To 
those who have interested themselves in the recent contest con- 
cerning geological types of the older strata, this work affords 
abundant matter of interest, and its individual character is 
fully explained by the circumstance above described. 
Description of the Skeleton of an Extinct Gigantic Sloth 
[Mylodon Robustus), with observations on the Osteology, 
natural Affinities, and Habits of the Megatherioid Quad- 
rupeds in general. By Richard Owen, F. R. S. Van 
Voorst, 4 to. 
This work is published by order of the Council of the 
Royal College of Surgeons, and independent of the interest 
which belongs to it as explanative of another extinct animal, 
we cannot refrain from observing that we think the generali- 
zations on Megatherioid quadrupeds by far the most interest- 
ing portion ; it shows, moreover, how successfully the com- 
parative anatomist may reason when the number of distinct 
observations is sufficient for his purpose, and that the dull 
routine of recording peculiarities of one fossil representative 
of an extinct family or genus, is amply repaid by the remark- 
able discoveries of natural affinities which are demonstrated 
by subsequent comparisons. 
