84 



In America some attention has lately been devoted to fossil 

 insects by Dr. Dawson, F.K.S., Pi'ofessor Denton, Dr. Horn, Mr. 

 Mead, Professor Dana, Mr. Richardson ; and especially by that 

 distinguished Entomologist, Mr. Samuel H. Scudder, to whose 

 numerous writings, especially his exhaustive essay on " Fossil 

 Butterflies," recently published in the Memoirs of the American 

 Association for the advancement of Science, constant reference 

 Avill 1)0 made throughout this paper. 



Among other important contributors to our knowledge of 

 fossil Entomology must be mentioned Gravenhorst, Charpentier, 

 Giebel, Carl Von Heyden, Lucas Von Heyden, Saporta, Ehren- 

 berg, Pictet, Unger, Berendt, Germar, Goldenberg, Boisduval, 

 Hagen, Von Miinster, Massalongo, Van Beneden, Preudhomme de 

 Borre, Adolphe Brongniart, &c. 



I now propose to refer briefly, in the descending order of 

 Geological succession, to the various British and Foreign forma- 

 tions of the Eecent and Tertiary Periods in which remains of 

 insects have been detected, and to enumerate, as far as possible, 

 the several orders and species to which such remains have 

 severally been assigned. 



Before doing so, it will be desirable to make a few observa- 

 tions on the probable circumstances under wliich insects became 

 embedded in certain strata in Avhich their remains have been di^;- 

 covered. 



The estuarine and purely fresh-water formations are, as would 

 naturally be expected, those in which the remains of insects have 

 been found in the greatest quantities, but their remains have also- 

 been discovered, and in some cases in considerable numbers, in 

 ]\larine formations, such as the Stonesfield Slate of England and 

 the Solenhofen Slate of Bavaria. Their presence in such 

 formations may be accounted for by supposing them to have 

 been blown or washed out to sea from some neighbouring 

 land ; or to have been blown into the sea Avhen attempting 

 to cross it, and then, sinking to the bottom, have becomt- 

 embedded in the sediments there accumulating. 



