264 Rev. F. 1). Morice's Notes on Australian Sawfiies. 



long ago by Aristotle's master Plato. He compares it to 

 the methods of an unskilful butcher (xaxog udyeigoq), 

 cutting up his carcasses without regard to their "natural 

 articulal ions " (doOna f\ neq. uhs), and therefore not inserting 

 his knife between the meeting-points of the limbs, but 

 hacking through the bones themselves. This, I venture 

 to think, exactly describes the manner in which Leach's 

 genus has been dealt with by such writers as Shipp and 

 Ashmead — of whom the former was evidently incompetent 

 to deal with it at all, and the latter, though versed in the 

 lit cf<ilnr<' of the subject, seems to have had no actual 

 acquaintance with any of the species, whose affinities he 

 took upon himself to determine. 



Xyloperga, Shipp, however (— Heptacola, Konow), is 

 at any rate a real group, and differs from normal Perga, 

 not only in its mouth-parts, and the other characters 

 mentioned infra in my Table, but in sundry other details 

 such as a peculiarity in the form of its clypeus, which is 

 rather difficult to describe but easy to recognise when once 

 thoroughly realised. It is (approximately) bisected trans- 

 versely into two distinct areas, a basal and an apical, the 

 latter being occupied (except at its extreme apical margin, 

 which is a little recurved) by a sort of shallow sulcus above 

 which the basal area rises somewhat abruptly to a higher 

 level. The division between these higher and lower levels 

 is nearly a straight line, so that the clypeus appears to 

 have a double apical margin, or, in other words, to end 

 before its real apex. Something of the kind occurs also 

 in one group of Perga (bella, etc.). in which and also 

 in certain spp. of " Heptacola " (i.e. Xyloperga) Konow 

 describes the phenomenon as "Clypeus in der Mitte quer 

 gebrochen," but he docs not utilise it as a general character- 

 istic of the latter genus. 



The scutellum, also, of Xyloperga (as pointed out by 

 Konow) is somewhat more narrowed posteriorly than in 

 normal Perga spp. (subtriangular rather than oval or 

 subquadrate), and this generally brings the " apical lobes '" 

 rather nearer together than in the other case. 



Unfortunately most of the forms which make up Xylo- 

 perga are represented by at most one or two specimens in 

 B.M. and at Oxford. The only species of which I have 

 seen anything like a series is univittata, W. F. Kirby. which 

 Konow. quite wrongly, sinks as the o °f " neirmainii." 

 Westw. ( ■ ferrnginea, Leach). Konow is also mistaken 



