WASP-GENUS PARALASTOR. 565 
is interesting to note that the four members of this last colour- 
group that are at present known fall each in a totally different 
group structurally. Of course, W. Australia has species other- 
wise coloured, which resemble those from other parts of the 
country. 
North Queensland has a number of species remarkable for the 
ornamentation being nearly confined to the large 2nd abdominal 
segment, the pattern of this being very distinctive, sometimes 
ferruginous, sometimes yellow or nearly white. 
It is evident that many and perhaps most of the species exhibit 
considerable variety in colour or pattern of colour, as also in 
smaller details of structure, but to what extent this is the ease, 
whether as regards individuals from one station or those from 
separate localities, the material at my disposal is far too limited 
to decide. This material consists of the British Museum Collec- 
tion, excluding the actual types of Saussure and Smith (most of 
which, however, I have examined), of the collection in the Hope 
Department of Zoology in the Oxford Museum, including types, 
and of my own collection. The total number of specimens is 
only 333, although 2000 or more would hardly be adequate for 
dealing with the genus satisfactorily. Moreover, as six species 
together account for 101 of the 333 examples, it will be seen that 
about 90 species are represented very poorly indeed. There is 
no doubt that great numbers of species and local forms remain 
to be discovered, and the genus will ultimately prove to be very 
difficult. Even at present the species are not at all easy, com- 
pared with the Hawaiian Odynerus, which about equal them in 
number. 
A great deal of the material in the British Museum and at 
Oxford is very old and often dirty, and has, further, been badly 
mishandled in the desire to extend the wings. 
In Alastor, Odynerus, and kindred genera, the abdomen should 
always be kept flat on the ventral surface, and not bent at the 
suture between the first and second abdominal segments, as is often 
the case. It should, however, be bent downwards at the petiolar 
articulation, so as to fully expose the propodeum. If properly 
mounted in this way, the base of the second ventral segment will 
be fully exposed and the structure of the segment readily observ- 
able. Tio anyone who has handled many hundreds of species of 
Kumenidz, proper preparation of the specimens is of minor con- 
sideration, as he will easily make allowance for the retraction or 
flexure of the second ventral segment, but to one not so circum- 
stanced, the difference in appearance caused by poor preparation 
may be a source of serious error. 
Two species which I have described on single specimens have 
not the neuration of Paralastor, but of Odynerus, the second 
cubital cell not being petiolate. Whether they are constant in 
this character or not, remains to be proved. It isin any casea 
very feeble one, for in some species the petiole of the cell is very 
much reduced, so that it was quite certain that sometimes, either 
