92 PALEONTOLOGY 



including the Reduviidse, Lygaeida?, Hydrometridae and 

 Belostomatidae, existed at this period. The Pala^ontinidse from 

 the Solenhofen slates, which are regarded by Handlirsch as the 

 earliest known Lepidoptera, are referred by Tillyard to the 

 Homoptera and appear to have been Cicada-like forms. It is 

 also noteworthy that Mecoptera occur plentifully in the Lower 

 Lias of England. Among the genera are Orthophlebia, which 

 appears to be ancestral to the living Panorpidse, and Probittacus, 

 which connects the recent Bittacidse with the Permochoristidae, 

 The sub-order Paratrichoptera also extends into the Lower Lias 

 where it is represented by a fore wing of Liassophila from rocks 

 in Warwickshire (Tillyard, 1933). 



Cretaceous. Only scanty and fragmentary remains of insects 

 occur in rocks of this date. On the whole, Coleoptera pre- 

 dominated in the Lower Cretaceous of England, and the Upper 

 Cretaceous of Bohemia. Fragments referable to other orders 

 have also been disclosed in the last-mentioned strata, but they 

 are, for the most part, too 230orly preserved for accurate deter- 

 mination. The most considerable recent discoveries among 

 Cretaceous insects are those of Ping (1929) in China, where a 

 wide and very scattered series of forms has been disclosed 

 ranging, among the higher orders, from Paraulicus (Evaniidse) 

 and Chironomidse to Perlidae and Blattidae. All the examples 

 disclosed in China appear to belong to existing families. Taken 

 as a whole the insect remains during Cretaceous times are scarce, 

 but this is not to be attributed to actual paucity of those animals 

 during that period, but rather to the absence of suitable fresh- 

 water deposits wherein examples might have accumulated and 

 become fossilised. The comparatively sudden appearance of 

 highly organised Lepidoptera, Aculeata and cyclorrhaphous 

 Diptera, in the early Tertiary period, suggests that these groups 

 must have been represented by forerunners in Cretaceous times. 



Tertiary. Many of the Tertiary deposits are extremely rich in 

 insects and they have yielded nearly three-fourths of the known 

 fossil species, almost all modern orders being represented. Taken 

 as a whole the fauna of these times did not differ markedly in 

 composition from that of to-day — even during the Oligocene, 



