BY R. J. TILLY AKD. 271 



one cjI' tljem in a magnificent state ot preservation, and two fragments of hind- 

 wings. The type of wing represented by this material turns out to be very 

 different from what 1 had surmised on the basis of the original fragment. They 

 are evidently the wings of true Homoptera, but so unlike any known forms that 

 I was for a long time in doubt as to where to place them, and tinally decided to 

 allot a separate Part to them, so as to allow of a full discussion of their true 

 affinities. In this study I have had the good fortune, during my recent voyage 

 round the world, to see for myself, and to study carefully, the types of two of 

 the Jurassic fossils of the family Falaeontinidae, viz. I'ulaeoritina uulitica Butler 

 and Eocicuila lameerei Handl., together with a number of uudeseribed specimens 

 of this family from Solcnhofen, which are in the Collection of the Museum of 

 Comparative Zoology at Cambridge, Mass., U.S.A. This family has been placed 

 by Handliisch in the Order Lepidoptera. As will be shown in this paper, they 

 are, as a matter of fact, a family of extinct Homoptera related to the Cicadas, 

 as Oppenheim and Haase originally considered some of them to be. The genus 

 Mesogereon is closely related to these Jura.ssic insects, and through them to the 

 existing Cicadas also. 



A careful study of the four forewings of Mesogereon (inclusive of tlie 

 original fragment) shows that there are so many important differences that no 

 two of them can be considered as conspecific. The original type of the genus, 

 Mesog-ereon neuropunctatum Till., bears the number 19a of the Collection of 

 Ipswich Fossils in the Geological Survey at Brisbane. The next specimens to 

 be received were Nos. 206o and 207o. Of these, the former is a fairly com- 

 plete forewing, with some of the apical border missing, and manj- of the main 

 veins badly buckled at about two-thirds their lengths. This wing will be de- 

 scribed as Mesogereon affine, n.sp. in this paper. No. 207a appeared to be, 

 at first sight, an entirely different and much smaller wing. It was found only 

 a few inches away from No. 206a, in the same layer of shale. After making 

 careful drawings of this wing, which is by no means complete, I was struck witli 

 the fact that it possesses several peculiarities closelj- comparable with those to 

 be found in the forewings of Mesogereon, and quite unlike anything else known 

 in the Ipswich fossils. I therefore concluded that this speeiuien was part of 

 the hitherto unknown hindwing of this genus. As it was found so close to No. 

 206aj I have decided to consider it as the hindwing of M. affine, n.sp., though, 

 of course, it is impossible to prove this strictly, as the two wings were not 

 attached in situ to the body of one insect. 



Just before I left Australia in April, 1920, Mr. Dunstan forwarded me the 

 remainder of the material dealt with in this paper. This consisted of three 

 specimens numbered 169, 144a and 97 respectively. No. 169 is a magnificen! 

 wing, complete except for a small piece missing from the costal mai'gin and 

 another small piece from the apex. Its state of preservation is so perfect that 

 even the impressions of some of the hairs carried by the maerotrichial sockets 

 on the wing-membrane are visible, and have been most beautifully photographed 

 by Mr. W. C. Davies in Plate xvii., fig. 19. The ambient vein and coriaceous 

 border (Plate xviii., fig. 20), typical of the Homoptera, are here, for the first 

 time, shown in their perfection, leaving no doubt as to the correct placing 

 of these insects in the Order Homoptera. This wing is here described under the 

 name BI. superbum, n.sp. No. 97 is a hindwing, more complete than No. 

 207a. It shows, for the first time, a small portion of the ambient vein and 

 coriaceous border (Plate xxi., fig. 25) resembling those of the forewing, and thus 

 definitely settling the question as to the genus to which these two wings belong. 



