280 



IIESOZOIC INSECTS OF QUEENSLAND, Xlll., 



the bend at tlie ciosb-vein less marked. M is three-branched, but it is the upper 

 braiu'h, Mi-l'. which divides into two, while the lower, M3-4, appears to run 

 straight to the termen. Cut divides into two at a level slightlj' distad from that 



T«xt-fig. 71. Mesogereoi! s/iep/ierdi,TD..s-p. Venation of hindwing. Missing portiona 

 restored by broken lines. For lettering, see p. 284. (x 4^) . Note the 

 presence of two r.adio-raadi;in crossveins, r-m. 



of the fii-st fork of M: the upper branch, Cuia, is connected with Ms -4 by a 

 strong cross-vein. (It would be possible to interpret this cross-vein as the basal 

 piece of M4; in which case M would become four-branched and Cui simple in 

 this species; it is not easy to say which interpretation is really the correct one). 

 The origin of Cu2 is not clear, but appears to be about half-way between cu-a and 

 the forking of Cui. The cross-vein eu-a is present near tlie liase, but somewhat 

 more obliiiue than in M. affine. 



Cross-ridges are absent on the main veins, but clearly [irosent on the 

 coriaceous border, a portion of which is preserved between tlic ends of veins Ra 

 and Ms. Tliis part of the wing is shown much enlarged in Plate xxi., fig. 25. 



T y p e, Specimen No. 97 in Coll. Queensland Geol. Survey, P.risbane, Q. 



H o r i z o n. Upjier Triassic, Ipswich, Q. 



Table of Snmr Imporhtnl Differenoein in the Forewinga of the Known Speeies 



of Mesogereon. 



(1) 

 (2) 

 (3) 



(4) 

 (5) 

 («) 

 (7) 

 (8) 



Measurements (in mm.). 



I 3/. neuro- 

 \puticiatuiti. 



M. SHperb- 

 um. 



Estimated total length. ! .50 - 60 



Rstiiimted total breadth. j LI - 17 



From fork of Rs to fork of M1+2. 1 

 B'rom fork of M1+2 to fork of M:i+t.j t-i) 



Basal piece of M4. 0-6 



Angles of Ml to fork of Cm. 



Ratio of (4) to (5). 6-7 



Ratio of (6) to (5). 



46 

 12 

 0-9 

 2-5 

 1-2 

 5-7 

 2-1 

 4-7 



""'■'^iT^Mralfin 



4.T 



12 



2-9 

 0-(i 



4-S 

 10-5 



40 

 12 

 2 3 

 2-4 

 0-9 

 ()•() 

 2-7 

 0-7 



