320 Rev. F. D. Monro's Notes on Australian Sawjlies. 



whole structure and bionomics of their larvae differ pro- 

 foundly. Larvae of Lydini have no abdominal pro-legs, 

 they have a most singular and characteristic developmenl 

 of certain anal appendages (cerci), in both which characters 

 they seem more "primitive" than normal Tenthredinidae ; 

 and though they teed on leaves, they are all the time con- 

 cealed in rolled leaves or silken webs, one such web being 

 sometimes spun in concert by a whole brood of larvae 

 feeding together gregariously. But my confidence on the 

 point was shaken when I found that several Australian 

 larvae, which seem to be Tent hredinid, possess no pro-legs; 

 that one of these (Philomastix) has also anal cerci developed 

 even more paradoxically than those of the Lydini; and 

 that the larvae of a certain Neogaeic Tenthredinid (Dielo- 

 cerus) are stated by Curtis to spin up gregariously in a sort 

 of joint-cocoon (27. Linn. Soc. Lond., 1844, p. 248). The 

 imagines of the Australian species above mentioned have 

 ante-apical tibial spines as well as the usual "calcaria"; 

 and putting all these facts together, 1 am tempted to think 

 that both these latter and the Lydini may have inherited 

 these characters from primitive Tenthredinid ancestors who 

 had not yet completely developed the structures and habits. 

 which have now become almost universal in the Family. 

 At present, therefore. 1 cannot bring myself to follow Konow 

 and Rohwer in uniting the Cephini with the Lydini as a 

 single Family or Superfamily apart from and on a level 

 with the Siriddae or Tenthredinidae. It seems to me 

 more probable that the Oryssidae, Siricidae and Cepidae 

 are subdivisions of one main group from which the Tenthre- 

 dinidae should certainly be excluded. The Lydini (= Pam- 

 philinae, Ensl.) may perhaps represent a primitive group of 

 Tenthredinidae which had branched oil' from the main stock 

 before it had developed certain characters (especially 

 abdominal pro-legs in the larva, and the manner of feeding 

 connected therewith) which are now almost universal in it 

 ■ — a few species, all Australian, being the only known excep- 

 tions. But even if this be true, it must remain a mere 

 hypothesis in the absence of palaeontological evidences to 

 support it. and such evidences must be admitted to be 

 wholly wanting. Such little knowledge as we possess of 

 the earliest representatives of the Sub-order has been care- 

 fully gathered and summarised in Handlirsch's great work 

 on Fossil Insects. But the results at most indicate it can- 

 not be said that they prove — that the Siricidae are a more 



