40.) NOTICES OF NEW BOOKS. 



the lias, both in its upper and lower members, a very large number 

 of insect remains, chiefly, as in the Wealden, from calcareous beds, 

 rarely more than a few inches in thickness, but remarkably per- 

 sistent over districts comparatively extensive.* The result of these 

 investigations is given in the volume now before us, the greater 

 part of the text of which is occupied by a minute detail of sections, 

 showing the position of the fossiliferous beds, containing insect 

 remains, but which includes, in a number of very beautifully ex- 

 ecuted plates, accurate representations of nearly 170 specimens, 

 selected from a much larger series, and illustrating every species 

 that can be at all distinctly made out. The drawings and the ento- 

 mological descriptions have been prepared by Mr. Westwood, and 

 the introductory observations and explanations of the plates by 

 that gentleman give considerable value to the work, and render it 

 an important contribution to British Palaeontology. 



The insects now described from the British secondary formations 

 consist of three groups, all of them belonging to what may be con- 

 sidered the middle secondary period, and characterising each one 

 of the three great subdivisions of that period, — the Lias, the 

 Oolites, and the Wealden. There is well known to exist a cer- 

 tain uniformity of character in the middle secondary fossils, and 

 many interesting palaeontological facts, some of which have been 

 long recorded, render it probable, that in England the whole 

 group of the middle secondary rocks was deposited at no great 

 distance from dry land, clothed perhaps with vegetation, and 

 certainly the habitation of many strange and hitherto little known 

 animals. Some, at least, of those whose remains have been handed 

 down to us, indicate, by their structure, that they fed on insects. 

 That the remains of insects, therefore, should be found in beds 

 of the period in question, in a fossil state, was antecedently pro- 

 bable, although the delicacy of such organic remains might render 

 it unlikely that they should have been preserved, except locally, 

 and under peculiarly favourable circumstances. 



The analogies of the insects made known to us by the discoveries 

 of Mr. Brodie with animals of the same class at present existing, 

 is a point for which palaeontologists were also to a certain extent 

 prepared by the previous descriptions given of those from the 

 upper Jurassic rocks of Solenhofen, where forms occur so strictly 

 resembling existing species, that it is difficult, in the absence of 

 perfect specimens, to distinguish between them. Mr. Westwood's 

 remarks on this subject are interesting and valuable. 



As many as 300 specimens of insects of various kinds from the 

 lias were examined by Mr. Westwood, and of these considerably 

 more than one third consisted either of beetles, for the most part 

 rudely preserved, or of their elytra, nearly ninety of the specimens 

 consisting of single elytra or the two elytra detached from the body. 



* It is to Mr. Brodie also that Paleontologists are indebted for the discovery 

 of other minute fossil bodies of great interest, especially the remains of fishes 

 in the Silurian strata. 



