208 REVISION OF THE THYNNID.E OF AUSTRALIA, I., 



pygidium of the female. During coupling the female is carried 

 by the male, apparently for the greater part of the day. When 

 restin*^ or moving on a leaf or flower the female is extended 

 behind the male, both with the under surface against the leaf. 

 During flight the female hangs below the male in a doubled-up 

 position; the mandibles being applied to the basal part of the 

 hypopygium, which is held depressed at right angles to the 

 abdomen of the male and the aculeus, or sometimes the carnia 

 beneath the hypopygium, inserted between the maxill?e of the 

 female. Thus it is possible that there may be a connection 

 between the structure of the hypopygium of the male and the 

 mouth-parts of the female. The male of Diaiama does not carry 

 the female, the former being much the smaller; and in this group 

 the hypopygium is unarmed and the female mouth-parts fully 

 developed. In other genera in which the hypopygium is unarmed 

 the female does not seem to be taken with the male as often as 

 in other species, though some species of Eirone seem to form an 

 exception. 



The classification of the group is difficult; Guerin and West- 

 wood founded a number of genera, using the mouth-parts more 

 especially. Some of these genera will certainly stand, and all, 

 being founded on careful dissections, are worthy of consideration 

 and should not be sunk hastily. Saussure uses the hypopygium 

 as a basis for his classification, but only forms one new genus; 

 whereas Klug used the mouth-parts and avoided subdivision as 

 much as possible. Smith, unlike previous authors, paid very 

 little attention to classification, practically confining himself to 

 the description of new species. Of late years Ash mead has 

 attempted a more detailed classification of the group, taking the 

 hypopygium of the male and the pygidium of the female as the 

 basis. This basis is open to criticism, for, as has been pointed 

 out above, these parts do not appear to be co-related, so that we 

 cannot expect the two sexes to fall into parallel lines if this basis 

 is used. There should be some connection between the form of 

 the pygidium in the female and the claspers in the male, but the 

 study of the latter organs will require much more material than 



