74 PALEONTOLOGY 



of Belmont and Newcastle, New South Wales : the discovery and 

 exploration of these rocks is largely due to J. Mitchell ; (3) the 

 lower Permian Beds of Kansas, U.S.A. : originally discovered by 

 A. C. Sellards of Yale, they have been explored by the Yale 

 University Expedition under C. Dunbar and more recently by 

 F. M. Carpenter of Harvard ; (4) the Upper Permian Beds of 

 North Russia : these have been explored during 1926-28 by 

 A. B. Martynov and M. Edemsky. Of these four series the most 

 important are those of Kansas, and many of the insect remains 

 preserved in these beds are among the most perfect so far known. 

 A number of the specimens show the colour-pattern and the finest 

 details of the trichiation on the veins and membrane of the wings. 

 In addition to the foregoing, mention needs to be made also of 

 studies by Martynov on the Jurassic insects of Turkestan ; by 

 Ping on the Cretaceous insects of China ; and by Tillyard on 

 Liassic forms from Europe. 



Orders only Known as Fossils 



The palaeozoic and earlier mesozoic fossil insects include 

 representatives of orders which no longer exist at the present 

 day. The chief extinct orders, including those brought to light 

 by recent research, are the following. 



Palaeodictyoptera Gold. The oldest and most primitive order of 

 winged insects and its members are characterised by the following 

 features. The head is rounded and bears setaceous antennae. 

 The prothorax is generally provided with conspicuous lateral notal 

 outgrowths resembling vestigial wings. The mesothorax and 

 metathorax are subequal in size and subquadrate in form. The 

 wings are elongate and attached to the thorax by broad bases : 

 the two pairs are closely alike in form and venation, the hind 

 wings being without the fan-like anal lobe characteristic of many 

 early groups. The venation is more complete than in any other 

 insects (tide Lameere, p. 19), and its outstanding features are 

 (1) the greatly developed branching of most of the principal 

 veins ; (2) the presence of well-developed branches MA and MP to 

 the media ; (3) the retention of at least three, and usually more 

 than three, anal veins or branches ; and (4) the presence of an 



