85 



It is well known to all Entomologists that insects migrate in^ 

 vast armies, frequently crossing the sea to effect their puriiose. 



Pierts Rnpce (the Common Garden White Butterfly) has been 

 known to cross the Channel from France to England in a dense 

 swarm. On this subject an eye witness has written, " Such was 

 the density and extent of the cloud formed by the living mass, 

 that it completely obscured the sun from the people on board the 

 steamer for many hundreds of yards, while the insects strewed the 

 decks in all directions." 



]\Ir. Bates in his book on the " Amazons " mentions several 

 instances of the flights of insects over the sea. Swarms of 

 locusts have been observed many hundreds of miles from land 

 and moths, dragon flies, and other insects, have alighted on the 

 decks of vessels in mid-ocean. The occasional presence of fossil 

 insects in Marine formations may be thus accounted for; but 

 where their remains are detected in any abundance in such 

 formations, the proximity of dry land at the time of their 

 deposition maybe generally assumed. 



AVherever insects have been discovered in a fossil state the 

 Coleoptem are generally very numerous. This is easily accounted 

 for by the hardness of their elytra. 



The comparison of existing species of insects with the 

 fossilized fauna of the ancient world, and the study of their 

 Geographical distribution, is one of the most interesting features 

 in this branch of Science. It is Avorthy of note that the 

 insects, even from the older strata (e.g., the Lias) are far 

 more closely allied to those now in existence than the 

 rest of the fauna of the Ancient World, and although 

 some of them cannot be identified with any living types . 

 still there is, as Mr. Brodie observes, "a much less proportional 

 difference in this respect than might fairly be expected ; so that 

 these fossils may be almost said to afford an exception to the 

 usual conclusions which have been derived upon this subject." 



