REVIEWS. 



An Introduction to Paleontology. By A. Morley Davies^ 

 D.Sc. pp. xi, 414. London: Murby & Co. 1920. 12s.6fZ.net. 



rpHE task of writing a small textbook on the palseontology of 

 -^ both animals and plants, suitable for students who have had no 

 biological training, is one of great difficulty ; but much may be 

 expected when such a task is undertaken by an experienced teacher 

 who, as shown by his work on the Geography of the British Isles, is 

 also a lucid writer. 



Instead of the more usual method of describing first the zoological 

 characters of each group, the author begins with an account of the- 

 hard parts of some typical fossil forms, and then refers to the 

 characteristics of the soft parts as seen in living representatives ; 

 but whether this, without illustrations, will give students a 

 satisfactory idea of the zoological characters of the group seems 

 doubtful. The order in which the various groups are taken is : 

 Brachiopoda, Lamellibranchia, Gasteropoda, Cephalopoda, Trilobita 

 and other Arthropoda, Vertebrata, Echinodermata, Graptolites, 

 Corals, Porifera, Protozoa, Bryozoa (Polyzoa), Annelida, Plants.. 

 No reason is given for this order, and it would have been easier for 

 the non-biological student to understand the relationship of the 

 groups if a table of classification had been given at the beginning 

 of the book. Similarly the use of the same kind of type for the names 

 of groups of different value — Phyla, Classes, Orders, Genera, etc. — 

 does not make for clearness. Very unequal treatment is accorded to 

 different groups ; thus 68 pages are devoted to the Class Cephalopoda, 

 but the great Phylum Arthropoda (other than Trilobites) is disposed 

 of in 4 pages ; the Vertebrata receive 18 pages, and Plants 13 pages. 

 The accoimt of the Cephalopoda seems to be more detailed than is 

 suitable for elementary students, and would have been easier to follow 

 if it had been divided into three sections dealing with the Nautiloidea, 

 the Ammonoidea, and the Dibranchiata respectively. 



While some parts of the book have the style of a lecture, others, 

 notwithstanding the author's prefatory remark, approach closely 

 to tho form of a descriptive catalogue. The author is certainly 

 not sparing in the use of technical terms, and in some places gives 

 the impression of trying to introduce as many as possible ; this will 

 certainly not prove an attraction to non-biological students. The 

 two chapters on " Kules of Nomenclature " and " Divisions of 

 Geological Time ", although valuable for advanced students, seem 

 out of place in an elementary work, and we think the space might 

 have been put to better use by giving a more adequate account of 

 some of the groups of fossils which are dealt with too briefly. 



The original illustrations are satisfactory, but the figures 

 copied from other authors have not in all cases been well chosen ;. 

 for instance, in the echinoids the figures generally omit or show 



