BY R. J. TILLY ARD. 715 



build of the inseet, but also upon the form of the resting-surf ace ; 

 as, for instance, in the case of the Psyclwpsidae, in which that 

 angle is very acute when the insect rests upon a twig, and very 

 obtuse when it rests upon a flat surface. In the more archaic 

 Orders Mecoptera, Megaloptera and Planipennia, the stegoptcr- 

 ous position of rest is practically universal. Jn the Trichop- 

 tera, it is the usual condition in all but the specialised Hydrop- 

 tilidae. In the Lepidoptera, the stegopterous position is that 

 adopted by all the Homoneura, and by many of the older forms 

 within the Heteroneura. In the Diptera, the same position of 

 rest is seen in the case of the Psychodidae, while the. position of 

 rest in the Tabanidae and many of the Cyclorrhapha (as in the 

 Blowfly) shows little alteration from it. 



The conclusion to be drawn from this is that, as regards the 

 resting-position of the wings, the whole of the Complex was 

 originally the same. The evidence, then, is in favour of a 

 monophy'etic origin for the Orders of the Complex, and helps 

 to strengthen the conclusions already arrived at, from a study 

 of the wing-coupling apparatus, the trichiation and the venation. 



The stegopterous position of rest is found also in certain 

 Orthoptera, and in the Psocoptera and the Homoptera. It is a 

 more specialised position than the position with wings outspread 

 (as in Anisopterous Odonata), or lifted vertically up over the 

 body (as in Plectoptera), but more archaic than the flattened- 

 down condition found in the Blattoidea, Perlaria (in which, also, 

 the wings are more or less curved round the body), Heteroptera, 

 Hymenoptera, etc. 



BIBLIOGRAPHY. 



(Note. — The reference numbers are made consecutive from Part to 

 Part, but only those referred to in any given Part are printed with that 

 Part). 



2. Handlirsch, A., 1908. — Die Fossilen Insekten. Leipzig, 1908. 



3. Metrick, E., 1895. — " Handbook of British Lepidoptera." London, 



Macinillan k Co., 1895. 



5. Tillyard, R. J., 1917. — " Mesozoic Insects of Queensland. No. 1. 



Planipennia, Trichoptera and the new Order Protomecoptera." 



These Proceedings, 1917, xlii., Pt. i., pp.175-200. 

 6. 1918. — " Permian and Triassic Insects from New South 



Wales in the Collection of Mr. John Mitchell." I.e., 1917, 



xlii., Pt, iv., pp.720-756. 



9. Meyrick, E., 1917. — "Descriptions of South African Lepidoptera." 

 Ann. S. African Mus., 1917, xvii., Pt. i., No. 1, pp.17-19. 

 ( Prototheoridae, pp.17-19) . 

 12. Tillyard, R, J., 1916. — "Studies in Australian Neuroptera." 

 No. iv. I.e., 19Ki, xli., Pt. ii., pp.269-332. 



