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course intermingled at rare intervals with marine exuvioe, 

 as in the Lias for example. In some instances no doubt, they 

 might be carried further out to sea by violent winds, and be 

 then deposited at much greater distance from the land ; but 

 in this case, they would soon become a prey to numberless 

 hungiy fish, and only a few be embedded in the sediments 

 accumulating in the depths below. It is a known fact, and 

 stated by Mr. "Wallace, that living lasects cross great 

 breadths of water, for live Beetles have been caught at 

 sea, twenty miles from the shore. Swanns of locusts fly 

 from Africa to Madeira, (300 miles,) and moths have been 

 captured 260 miles from the coast of Portugal, dragon flies 

 have been observed a long way from land, often alighting 

 on the rigging of vessels in mid ocean, and a white butterfly 

 was caught nearly 400 mUes fi-om the Azores. Bates, in 

 his tour on the Amazons gives similar testimony as to the 

 occasional flight of Insects over the ocean, and at greater or 

 less distance from any coast. It would be interesting to 

 know by actual experiment, how long an Insect could 

 remain in the water before decomposition took place, and 

 under what conditions they would be most favourably pre- 

 served. On this point it is stated by Dr. Hagen, an 

 excellent authority, that the wings of Insects (which form 

 by far the largest portion in British strata,) are almost 

 indestructible in water. He had kept the wings of dragon- 

 flies in water for years without observing the slightest 

 change in their texture. The wing covers of beetles, and 

 beetles themselves, would be perhaps of all the Insect tribes, 

 the most likely to be fossilized, which is found to be the case 

 in fact, and the wings of the Libellulidoe and Locustoe 

 would perhaps be, as they really are, the next among them 

 least likely to be preserved. 



