886 



MESOZOIC INSECTS OF QUEENSLAND, vii., 



off a strong transverse veinlet (probably R x ) before half-way, 

 then running straight and without any branches for some distance, 

 and finally becoming slightly zig-zagged distally, giving off two 

 more veinlets to the costal margin, and connected with M 1+2 by 

 two cross-veins. Main stem of M very weakly chitinised; it 

 divides into two about the middle of the wing, and remains weak 

 for the basal half of the length of the median cell (mc) after 

 which it becomes more strongly marked. Median cell (mc) of 

 normal form, closed distally by a cross-vein, and connected below 

 by another cross-vein with Cu la . Distal fork of Cuj very 

 small; Cu lb ending up at an appreciable distance from the end 

 of the vena dividens. On the clavus, 1A is waved, but diverges 

 very little from Cu 2 ; 2 A encloses the anal angle. 



Genotype, Mesojassus ipsviciensis Till. (Upper Triassic 

 of Ipswich, Q . ) 



My original definition of this genus (8, p. 34) was very in- 

 complete, as I had not then succeeded in obtaining a really good 

 drawing of the fossil, in which the impression of the venation is 

 weak, especially in the region of M. The drawing given in 

 Text-fig. 17 was made under exceptionally good conditions in very 

 strong, oblique, evening sunlight, and adds much to our know- 

 ledge of this interesting fossil form. In the original generic 

 definition, the condition of the pitting of the wing was included . 

 I do not now regard this as of more than specific value. The 

 genus itself is not far removed from the recent genus Jassus. 



Mesojassus ipsviciensis Till. (Text-fig. 17) . 



Mesojassus ipsviciensis Till., 1916, (8, p. 35, Plate 2, fig. 7) . 



Total length, 6.2 mm. ; greatest breadth, 2.2 mm. (The mea- 

 surements given in my original description were somewhat 

 smaller, owing to the limits of the tegmen not being clearly made 

 out) . 



The pitting of the tegmen is not quite as described by me 

 originally. The basal portion of the tegmen is fairly strongly 

 pitted, but the pits become more and more indistinct towards 

 the distal end. Transversely across the middle of the wing 

 there is an indication of a change in the amount of pigmenta- 

 tion, the basal half being somewhat darker than the distal ; but I 

 do not think that this line indicates the limit of any special 

 development of the pitting. 



