37 



it was the ssme in Australia in the Trias as it is to-day, and that 

 the Australian fauna then, as now, combined numerous archaic 

 types with certain highly specialised forms peculiar to the continent. 



It is obvious that such an assemblage of forms can be of little 

 value in fixing the horizon of the strata in which they occur. Their 

 value lies rather in their application to the phylogeiiy of the Insecta. 

 In the record of fossil insects so far discovered, the Trias is exceedingly 

 poor, numbering only a few species of Coleoptera from Sweden and 

 Germany, and two genera apparently allied to the Megalopterous 

 genus Chauliodes, together with a few forms, mostly Coleoptera, 

 already described from Ipswich. Now the record of what we may 

 call the " Giant Age of Insects," first unearthed by Brongniart in 

 the magnificent deposits of Commentry in France (Upper Carboni- 

 ferous), can be followed with scarcely any break into the Permian. 

 Above this, in the Northern Hemisphere, comes the immense gap of 

 the Trias. When the insects again come fairly into view, in the 

 Lias of England and Germany, a very different and considerably 

 more specialised assemblage of forms is met with. There seems to be 

 no hope that this gap will ever be bridged by discoveries in the 

 Northern Hemisphere, since the Trias as a whole appears to be lacking 

 in fresh-water deposits of the kind in which we are accustomed to 

 search for insects. It is not unreasonable, therefore, to turn to the 

 Ipswich beds for evidence that will supply the missing links. How 

 splendid that evidence may yet prove to be, provided that these 

 fossils can be diligently searched for and preserved, this small first 

 haul of treasures amply shows. 



The chief general results of the discovery of these fossils may be 



/ 



briefly stated thus : 



1. Certain insect types characteristic of the late Palaeozoic 



in the Northern Hemisphere, and not found in the Mesozoic, 

 are now shown to have had fairly close relatives in the 

 Trias of Australia. Such types include Austromylacrites , 

 Mesorthopteron, and Mesomantidion. 



2. The first known appearance of a true dragon-fly, with 



nodus and pterostigma, can now be assigned to the Trias, 

 instead of the Lias. It was probably an Anisopterid. 



3. A Panorpid (Mecoptera), scarcely differing from a form 



still alive in Southern Queensland, existed in the Aus- 

 tralian Trias. This group has already been recorded from 

 the Lias in the Northern Hemisphere. 



