Rev. F. D. Monro's Notes on Australian Sawflies. 321 



ancienl group than the Tenthredinidae. The former are 

 represented in Secondary (Jurassic) strata by several forms 

 which are referred to an extinct genus, Pseudosirex, and 

 by a single very peculiar fossil, originally, but (teste Hand 

 lirsch) wrongly, described as an Ichneumonid (Ephialtites). 

 If this be really a Sawfly it must, I suggest, have been an 

 Oryssid. No Tenthredinidae or Pamphilinae occur in these 

 strata, and no Sawflies of any kind have been found in those 

 of Cretaceous or Eocene times. It is not till after the 

 earliest division of the Tertiary period that Tenthredinidae 

 and Pamphilinae begin to appear, namely, in the Oligocene 

 deposits, and as most of these fossil forms are stated (some- 

 times, perhaps, in error?) to belong to well-known existing 

 genera, they cannot be relied upon as fixing a date before 

 which these groups cannot have come into existence. It 

 is quite likely that they were already well established in 

 Eocene times at least, and perhaps in Cretacean, or even 

 earlier, for Siricidae certainly must have existed all through 

 these periods though we have no records of them, any more 

 than of the Tenthredinidae ! What is the precise relation- 

 ship between these great groups can as yet be only con- 

 jectured. Judging from their " characters " — and we have 

 nothing else to judge by — we may suppose that the Siricidae 

 are the earlier group, but whether the Tenthredinidae and 

 Lydinihad Siricid ancestors, or whether Siricidae -f- Cephini 

 + Oryssidae and Tenthredinidae + Lydini are respectively 

 earlier and later branches of a common stock are questions 

 which must here be left unanswered. Of one thing we may 

 reasonably feel sure, viz. that the earliest Tenthredinid and 

 Lydine genera were not differentiated exactly as are those 

 which now exist, and that therefore those representatives 

 of them that have been described from Oligocene deposits 

 are not the first generations of these Families. The original 

 ancestors may yet be discovered in earlier strata, or may 

 never be discovered at all. 



Note 3. — Characters of Australian and it on- Australian Saw- 

 flies compared or contrasted. 



If, as I believe is the case, the Sawflies of Australia are 

 all descended from Holarctic ancestors, it is natural enough 

 that we should be able to recognise among them far fewer 

 distinct and strongly characterised groups, than in many 

 Holarctic regions of an extent equal, or inferior, to that of 



