Mevieics — Br. C. Brongniarfs Primary Fossil Bisects. 233 



The six articles make a very useful and readable volume, which 

 every geologist should possess. They are full of valuable facts and 

 suggestions, and are the result of long years of patient and careful 

 observations and study by one of the most able geologists of this 

 century ; and, although we may not agree with the author in all 

 his views, we cannot but feel interested in the subjects be so ably 

 lays before us. 



II. — The Fossil Insects op the Primary Periods. By Dr. 

 Charles Brongniart, of the Natural History Museum, Paris. 

 (Recherches pour servir a I'histoire des lusectes Fossiles des 

 Temps Priraaires). St. Etienne, 1894.i 



TFHIS valuable monograph is the result of sixteen yeai's' continuous 

 A devotion on the part of the author to the study of that remark- 

 able Palaeozoic insect fauna, so wonderfully preserved in the fine 

 Coal-shales of the Commentry Collieries, situated in the Department 

 of the Allier, Central France. 



Some fifty or sixty years ago the acknowledged rarity of fossil 

 insects in strata older than the Wealden or Lias, and their unrecorded 

 existence in Palaeozoic rocks, naturally led to false assumptions to 

 account for their absence ; climatic conditions being alleged as 

 noxious and unfavourable to air-breathing animals. Since that 

 period, however, isolated discoveries in the Coal-measures of 

 England, Germany, and America have shown how unsafe it is to 

 generalize from negative evidence in speculations of this kind. 



It has been reserved to one favoured locality in a circumscribed 

 area of Central France to furnish more specimens of fossil insects 

 and in a better and more complete condition than in all the 

 previously known localities of the world put together, thus 

 showing that insects were abundant, as might have been anticipated 

 from the rich forest growth of the period, and that the existence 

 of insect feeders as Spiders, Scorpions, and insectivorous forms of 

 Reptilia might also have been prognosticated. 



The discoveries at Commentry are entirely due to M. Henry Fayol, 

 the Engineer and General Manager of the Commentry Coal-pits, 

 whose enlightened zeal and careful attention to the fossil contents 

 of the strata in the works under his charge have yielded such ample 

 reward. 



One group of these fossil insects, the largest in point of number 

 of individuals, the family of Blattidee or Cockroaches, is only 

 outlined in its principal genera in the present work, Dr. Brongniart 

 reserving them for a special and more exhaustive study in a future 

 contribution. 



The monograph is divided into three parts, to which is added 

 an atlas of plates forming a separate volume. 



The first part gives an historical account of the works which have 

 been already published on fossil insects, followed by a bibliographical 



' This work forms the thesis presented by M. Brongniart to the Faculty of 

 Sciences, Paris, to obtain the grade of Docteur es Sciences Naturelles, which has 

 been recently awarded him. 



