1878 ] 55 



from the indestructible nature of tlieir elytra, insects belonging to 

 this Order are likely to Lave been preserved in far greater numbers, 

 and under much, less favourable circumstances, than insects of other 

 co-existing Orders, and may thus appear to have been comparatively 

 more abundant than they really were. 



Next to the Lias, in ascending order, follows the Oolite, in the 

 lower division of which is included the Stonesfield slate of England. 

 In this formation (Stonesfield slate) a few insects have been obtained, 

 chiefly Coleoptera, and two or three large species of Neuroptera, as 

 well as two supposed specimens of Lepidoptera, one of which has been 

 described and figured by Mr. A. Gr. Butler* as Palceontina ooUtica. 



Mr. Scudder, after an examination of this fossil (P. ooJiticd), was 

 of opinion that it belonged to the Homoptera and not to the liepidoftera. 

 Space does not here permit me to enter into any discussion on the 

 subject ; but as we have no evidence of the existence of true flowers 

 at this period, and as the Lepidoptera could not have existed without 

 them, there appears to be a considerable amount of probability in 

 favour of the correctness of Mr. Scudder's opinion as to the insect not 

 being Lepidopterous, but its location among the Homoptera by no 

 means finds favour in the eyes of Entomologists. 



From the Solenhofen slate of Bavaria and the Purbecks of this 

 country, both belonging to the Upper Oolite — in addition to Neuro- 

 ptera^ Ortlioptera, Coleoptera, and Semiptera, — we have the earliest 

 traces of Diptera, five of which are recorded from the first-named for- 

 mation and seventeen from the latter. One specimen of Symenoftera 

 is also recorded from the Solenhofen slate, and two from the Dorset 

 Purbecks. 



In the Cretaceous rocks so few traces of insects have been met 

 with, that it is unnecessary here to allude to them. 



Tertiary Period. 



We now pass into the Tertiary Period in which the Ihjmenoptera 

 first became abundant and generally distributed, and during which the 

 Lepidoptera, in all probability, first appeared ; at any rate, it is only 

 in strata of this age that remains of undoubted specimens of the last 

 named Order have been obtained. 



The occurrence of the Lepidoptera, and of the Bees amongst the 

 Jlymenoptera, at this period, is quite consistent with the then state of 



* " Lepidoptera Exotica," pp. 126—128 ; and the " Geological Magazine" for October, 1874. 



