374 Bibliographical Notices. 



the I'idges are quite worn away by continuous scraping against the 

 rock during the action of boring. A, pedal view ; B, side view. 



C. Shell similarly but more uniformly worn, from the sandstone at the 



east side of East Bay, St. Andi'ews. 



D. Unworn shell for comparison. This specimen being found in shale, 



a material much softer than sandstone, was but little worn, 

 llemoved from its burrow and kept loose in a tank for nearly three 

 months, tlie margin, unworn by boring, was found to be perfectly 

 sharp. 



ElBLIOGllAPHICAL NOTICES. 



A Guide to the Fossil Invertebrate Animals in the Department of 

 Geology and Palceontology of the British Museum (Natural 

 History). 1911. (Second Edition.) Price 1*. London : The 

 Trustees of the British Museum. 



Although, as is set forth in the Preface, " this book does not profess 

 to be a complete systematic treatise, but relates only to the speci- 

 mens actually exhibited in the Galleries," it is nevertheless to be 

 regarded as the most complete work on this subject, in a condensed 

 form, which has yet been published. This is no reflection on the 

 numerous other Guides published by the Museum on other groups 

 of the Animal Kingdom. They are all marvels of their kind, Mhether 

 looked at from the point of view of the text or from that of the illus- 

 trations, which are excellent and liberally distributed. It is a pity 

 that it is not more generally realized that these books are no mere 

 " Guides," but rather expert summaries of existing knowledge 

 profusely illustrated by Museum specimens. Such volumes would 

 be found of the highest value even to those who do not visit the 

 Museum from one year's end to another. 



The volume now under discussion was written by Dr. F. A. 

 Bather, the Assistant Keeper of the Geological Department ; and 

 herein we have a guarantee of its quality, for Dr. Batlier is one of 

 the most exacting of men where his own work is concerned, and 

 possesses besides an encyclopaedic knowledge of his subject, won by 

 years of laborious study. Among zoologists to-day there are some 

 who take a very serious view indeed of the old question " Dans un 

 nom qu'y a-t-il ? " To them it is much more important than the 

 thing named. Dr. Bather is not one of these, and he has enabled 

 those who have a mind to know Avhat this pother of names is about 

 by citing the case of a trilobite which was christened nearly a 

 century and a half ago. Those, however, who are interested in 

 zoolog)'^ and who wish to have a handy and reliable epitome of our 

 knowledge of extinct Invertebrates will find this work indispensable. 



