BY R. J. TILLYARD. 283 



but the tuberculation of the forewing is faintly indicated in places, and so is 

 the presence of the coriaceous border. 



Reviewing the above evidence as a whole, I am forced to the conclusion that 

 Handlirsch has committed a serious error in claiming that the Palaeontinidae 

 belong to the Lepidoptera, and more particularly in making the definite state- 

 ment that scales are to be seen on these fossil wings. As far as the material which 

 I studied can be considered typical of the family, there is certainly no evidence of 

 any Lepidopterous affinities. On the contrary, the general build of the insects, 

 the venational scheme, and what little can be discovered of the armature of the 

 wing and the structure of the margin, leave no doubt whatever in my mind that 

 the Palaeontinidae are closely related to the genus Mesogereon, and that both 

 have a less close connection with recent Cicadidae. Though it is not possible to 

 prove definitely that either Mesogereon or the Palaeontinidae represent the original 

 ancestors of the Cicadas, yet we can definitely state that those ancestors must have 

 closely resembled these fossils. 



Present knowledge of the genus Mesogereon would lead me to abandon my 

 former claim that they show any affinity with the Protohemiptera, as represented 

 by Eugereon, though I am still prepared to see, in the cross-ridging of the main 

 veins and the presence of a remnant of an archedictyon in the medio-cubital cell, 

 evidences of a descent from forms possessing a complete original mesh work of 

 weak veinlets, such as is found in most of the Carboniferous fossils. 



A restoration of the complete insect belonging to the genus Mesogereon 

 should show it as a Cicada-like insect having roughly-haired forewings held roof- 

 wise over a moderately stout and probably hairy body; the hindwing's smooth and 

 transparent, hidden beneath the forewings, and probably with the anal area 

 folded. There was no sound-producing apparatus comparable with that of recent 

 Cicadas. The voiceless, hairy Cicadas of the genus Tettigarcta, confined at the 

 present day to Victoria and Tasmania, perhaps represent the closest approach, 

 amongst living insects, to these interesting Upper Triassic fossils, whose dis- 

 covery cannot fail to add much to our knowledge of, and interest in, the Homop- 

 tera as a whole. 



Cawthron Institute, Nelson, N.Z. 7.3.21. 



List of Works Referred to. 



DOHRX, A., 1867. — Eugereon boeckingi nnd die Genealogie der Arthropoden. 



Stett. ent. Z.eit., pp. 145—153, fig. 1. 

 Haase, E., 1890. — Bemerkungen zur Palaeontologie der Insecten. iV. Jahrb. Min. 



Pal, ii., pp. 1—32, PI. 1. 

 Handlirsch, A., 1908. — Die fossilen Insekten, etc., Leipzig, W. Engelmann. 

 OrPENHEiM, P., 1888. — Die Insectenwelt des lithographischen Schiefers in Bayern. 



Palaeont., xxxiv., pp. 21.5 — 247, Pis. xxx., xxxi. 

 TiLLYARD, R. J., 1916. — Mesozoic Insects of Queensland and New South Wales. 



Queensland Geol. Survey, Publ. No. 253, pp. 1—47, Fls. 1—9. 

 , 1918. — Mesozoic Insects of Queensland. Part 4. Hemiptera Heterop- 



tera. The family Dunstaniidae. With a Note on the Origin of the Heterop- 



tera. Proc. Linn. Soc. N.S. Wales, xliii., Pt. 3, pp. 568—592, PI. lix. 



-, 1919. — The Panorpoid Complex. Part 3: The Wing- Venation. Proc. 



Linn. Soc. N.S. Wales, xliv., Pt. 3, pp. 533 — 718, Pis. xxxi. — xxxv. 



Note on the numbering of the figures. — The numbers of the figures in tiiis 



series of papers were intended to run consecutively from Part to Part. Owing to 



