A RECLASSIFICATION OF AUSTRALIAN ROBBERFLIES OF THE CERDISTU8-NE0ITAMU8 COMFL,EX. (DIPTERA— ASILIDAE). By G. H. Haedy, Walter and Eliza Hall Fellow in Economic Biology, Queensland University, Brisbane. (Seven Text-figures.) [Read 24th November, 1926.] For Australian Asilids, as also those of elsewhere, generic names are being used that were founded upon European species and without true regard to relationships. White pointed out these shortcomings very effectively when he made the first effort to put the more obscure Asilinae on a better basis. I am indebted to Professor M. Bezzi who has kindly supplied me with a number of Asilids representing the typical forms of their genera, thus enabling me to develop White's suggestions for improvement. White did not examine all the genera allied to those he dealt with and that may be related to Australian material ; one of these, Paritamus, he evidently overlooked, this being even more typically Australian in appearance, if not in relationship, than either ^.eoitamus or Gerdistus. I have not seen GlaTpTiyropyga under which Schiner described a species, the typical form being from Brazil. Many authors regard Asilns as being a genus that should incorporate others hitherto not very well defined and, therefore, would relegate such to a position of subgeneric value. There seems to be no difficulty, however, in dividing Asilus, used in that wide sense, into two very clearly defined groups. The scheme here proposed certainly holds well for all the Australian material yet known and, as far as I can gather, the same seems true, if suitable modifications are incorporated, for European and North American species. In Asilus and its allies the dorsal surface of the eighth abdominal segment is subequal to the seventh, convex above and flat below, and its appearance is that of a normal segment even when it is bare, black and shining. In Gerdistus and its allies, with which the present paper deals, the eighth abdominal segment of the female has an appearance quite distinct from that of Asilus. Typically it is compressed, the ventral half invariably being so. On those two Australian genera, Pararatus and Blepharotes, which strictly do not belong to either of these groups, it approaches the same form, but the ventral half of the eighth abdominal segment is not so closely amalgamated with the upper half. The upper half is but slightly compressed, showing a convex dorsal surface, and the ventral half is not quite so compressed as in Gerdistus, but the best distinguishing feature is to be found in the structure of the lamella. In Gerdistus, as also in Asilus, this appendage is cylindrical, but in Pararatus and Blepharotes it is quite differently constructed, being broad, flat, and somewhat arched. I have seen the organ in use on a species of Asilus that was ovipositing on a leaf, and it acted as a sensory organ, feeling for a vacant spot amongst a mass of eggs already deposited. The final cluster of eggs represented a mass of orderly rows, although they were not necessarily deposited in sequence along these rows, gaps being left and filled later, s
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