Rev. F. D. Morice's Notes on Australian Sawflies. 309 



case of " generalisation " and suggestive of antiquity in 



the group. 



The larvae of all other Hymenoptera are footless, but those 

 of the Sawflies invariably possess three jmirs of visible 

 thoracic legs even in such cases as that of the Siricidae, 

 where these legs are feebly developed and probably quite 

 useless. Here, again, the Sawflies' structure appears to 

 be more primitive, though the Hymenoptera are not the 

 only group in which the thorax of the larva bears no legs. 

 Also in the largest and most typical subdivision of Sawflies 

 most of the abdominal segments are furnished with pro- 

 cesses serving as legs (" pro-legs ") much like those of 

 Lepidopterous " caterpillars." Opinions differ as to the 

 origin of this character. Some have thought that the 

 ancestors of all insects possessed abdominal legs which 

 have now disappeared in all imagines and most larvae, 

 though they have survived in larvae of these two Orders, 

 but Handlirsch seems more likely to be right in holding 

 that in neither case have they been inherited from any 

 primitive common ancestors, and that such resemblance as 

 exists between the larval pro-legs of Lepidoptera and those 

 of certain Sawflies is merely " analogous," and consequent 

 on the similar habits and surroundings of the organisms. 

 Although a great majority of Sawfly larvae possess them, 

 these all belong to one only of several distinct Families 

 or " Superfamilies," into which most recent specialists 

 divide the Sub-order. Larvae which at all times live and 

 feed concealed in wood (Sirex, Oryssus, etc.), or in buds, 

 stems, reeds, stalks of cereals, etc. (Cephus, etc.), or wrapped 

 up in rolled leaves, or silken webs (Pamphilius, etc.), never 

 have pro-legs, having, in fact, no need for them, as we shall 

 see presently. 



(b) The character from which the " Sawflies " receive 

 their vernacular name in English (and also in French, 

 sc. M ouches -a -scie) 'is the serration or denticulation of a 

 part of their ovipositing organs, namely, the two bilaterally 

 symmetrical blades, placed side by side, and sliding freely 

 backwards or forwards along a supporting " backpiece " — 

 this also consisting of two bilaterally symmetrical parts, 

 not, however, freely movable, but bound together at 

 least at their bases, so that they must move together when 

 they move at all — with which they form receptacles for 

 their eggs. These blades have often a really striking resem- 

 blance to saws, and a part at least of their operations may 



