364 MESOZOIC INSECTS OP QUEENSLAND, vi., 



Of these two, we must select Triassoblatta as the older type; 

 because in it, Sc remains still not reduced to its full limit of a 

 single vein bounding the costal space distally. The radius in 

 this genus shows no strong double curving. This genus might 

 reasonably be put into the Poroblattinidce on the character of its 

 subcosta; but in other respects it comes closer to the Mesoblatt- 

 inidce, so that a slight extension of the definition, as given by 

 Handlirsch, will enable us to include it as the most archaic 

 member of that family. The other genus, Samaroblatta, agrees 

 with Rhipidublattina (Text-tig. 296) in its completely reduced 

 Sc, but differs from it in the strong double-curving of R, and in 

 the absence of branchings on the anal veins. It goes naturally 

 into the Mesoblattinidce . The same may be said of the third 

 genus Austroblattula, of which it does not seem necessary to give 

 a restoration. 



The assemblage of forms described in ibis paper, then, is just 

 such as we might expect to find in beds of Upper Triassic age. 

 We may note, however, the existence of a much more archaic 

 type in these same beds, in the genus Austromylacrites Tillyard, 

 described in a former paper (2, p. 13). 



Before proceeding to enter upon the descriptions of the new 

 fossils, I desire to express my grateful thanks to Dr. A. Eland 

 Shaw, M.R.C.S., F. E.S., of Wynnum, South Queensland, for his 

 valuable help and criticism upon this Part. The manuscript 

 and Text figures were sent to Dr. Shaw, who studied them care- 

 fully, and was able, owing to his great experience in the group, 

 to suggest a number of useful alterations. My chief discussions 

 with Dr. Shaw centred upon two points, viz., the method of 

 counting the branches of R, and the correct naming of the wing- 

 areas. Both these really depend upon the application of the 

 Comstock-Needham system of venational nomenclature to the 

 Blattoidea, which Dr. Shaw is as anxious to see established as I 

 am, though by long use he has accustomed himself tO the different 

 notation in vogue amongst Blattidists. As regards the branches 

 of R, it seems to me, after a study of the known fossil types, 

 that it is quite impossible to say what are the limits of R, and 

 Rs in Mesozoic and recent forms. I have, therefore, expressly 



