82 



PALAEONTOLOGY 



(Fig. 43), from the Lower Permian of Germany, and Mesotitan 

 Till, from the Middle and Upper Trias of New South Wales. 

 The Protohemiptera are among the largest fossil insects so far 

 discovered, and the wing-expanse of Eugereon boeckingi Dohrn. 

 is estimated by Handlirsch at 16 cm. Except for the discovery of 

 the head and prothorax of this remarkable fossil palaeontologists 

 would have been faced with a puzzling problem in settling its 

 affinities from the wing remains only. 



The Protohemiptera are characterised by pronotal expansions 

 very similar to those of the Palaeodictyoptera and Protoperlaria. 

 The head is rather small, with projecting mouth-parts of the 



Fig. 43. Eugereon hoeckingii Dohrn. Reproduced by permission of 

 the Trustees of the British Museum. 



piercing and suctorial type. The whole of the wing is covered 

 with a meshwork of delicate and very closely set transverse 

 veinlets. The venation is markedly reduced with R^ and Cuj 

 simple unbranched convex veins, but Sc is well develoj^ed and 

 gives off numerous costal veinlets. M is represented by MA only 

 and Cu2 is pectinately branched. 



Protocoleoptera Till. The order Protocoleoptera was founded 

 by Tillyard (1924) for an example of an elytron (or tegmen), about 

 24 mm. long, discovered in the Upper Permian of Belmont, 

 N.S.W. This specimen, Protocoleus mitchelU Till., appears to point 

 to the existence of a primitive order ancestral to the Coleoptera, 

 but having flattened teguminous elytra with straight sutural 

 margin and a complete system of venation. Tillyard, in 1928, also 



