318 Rev. F. D. Morice's Notes on Australian Sfcwflies. 



as the defective neuration of its wings ■■-. are suggestive 

 rather of " degradation." On the whole, it seems likely 

 that this is one of the oldest, and perhaps the very oldest, 

 of all groups included in the Sub-order, and the discon- 

 tinuity of its distributions may simply be due to its extinc- 

 tion in the intervening areas. Yet it is certainly very 

 puzzling, and to my mind even inexplicable, that Ophry- 

 nopus should occur only in Notogaea and Neogaea. and 

 should be represented in these very distant Regions by 

 forms which can only just be distinguished specifically, 

 unless we suppose that some unknown cause has interfered 

 with its natural dispersal. I believe, too, that one of the 

 two recorded European spp. of Oryssus (unicolor, Latr.) is 

 really an American form ; and Enslin has lately described 

 another sp., closely allied to the only other European 

 sp. (Abietinus, Scop.), from a most unexpected locality — -viz. 

 the interior of Africa ! 



For the two-fold division of the Sub-order adopted by 

 Linne, later systematists generally substitute one which 

 recognises either three " Families " (Konow) or four 

 "Families" (Enslin) or four " Superfamilies " (Rohwer). 

 The two latter authors agree in separating the Oryssidae from 

 the Siricidae, whereas Konow kept them together. These 

 two groups differ greatly in the structural characters of 

 the imago, but the larvae of Oryssidae seem to be entirely 

 unknown, and though we may be sure that they live enclosed 

 like Siricidae in timber it has never been ascertained 

 whether or no they feed on it. For certain reasons it has 

 sometimes occurred to me that they may be parasitical, 

 and I find from Rohwer's Studies of this group (1912) that 

 the same idea has suggested itself to others. If, however, 

 their structure and habits should prove to be identical with 

 those of Siricid larvae, I incline to think that the agreement 

 between the two groups would outweigh their differences, 

 and at any rate that these differences ought not to be 

 treated as equivalent to those which separate both alike 

 from the Tenthredinidae. It mighl be well, perhaps, to 

 leave this question open for the present, until Oryssid 

 larvae have been discovered, and their structures and life- 

 histories elucidated. 



The chief point on which systematists now differ is as to 

 the place which should be given in classifications to two 

 groups whose habits and structure seem to be hardly those 

 of either true Siricidae or true Tenthredinidae— namely, 



