Rev. F. D. Morice's Notes on Australian Sawflies. 317 



iinder.any circumstances exceedingly short. On the other 

 hand. Siricidae are constantly imported, as larvae (in 

 timber) over great distances on shipboard, or by rail, etc., 

 and when the transportation involves no great change of 

 climate they often become established in the new habitat, 

 nor is it necessary that material for their future ovipositions 

 should accompany them, for such is sure to be found who- 

 ever they may go. This, no doubt, helps to explain why 

 the range of some Siricidae is practically world-wide, even 

 when they cannot be said to be abundant anywhere, and 

 w T hy the distribution of others is so extraordinarily " dis- 

 continuous."' whereas that of Tenthredinidae, whether their 

 range be wide or otherwise, is almost always strictly " con- 

 tinuous." At the same time there are probably reasons 

 why the normal dispersals also of Siricidae should be less 

 restricted than those of Tenthredinidae. The imago of 

 the latter is commonly a soft-bodied, feeble, and rather 

 clumsy and awkward insect, timid and inert, incapable of 

 bearing rough usage, and disinclined to change its quarters 

 without necessity — in fact, its w^hole life is often passed on 

 or near the plant, on whose leaves it had fed as a larva. 

 Its wings, though ample, lack rigidity, and are usually far 

 less well adapted to prolonged flights than those of a Siricid, 

 even if it had instincts prompting it to undertake them. 

 The mere fact that its migrations would generally be only 

 from one leaf to another of the same plant, or from one plant 

 to another of the same sort growing hard by, would naturally 

 make its dispersal slower than that of a Siricid. for the $$ 

 of that group seem not imfrequently to oviposit at a con- 

 siderable distance from the timber out of which they have 

 emerged. They seem, too, altogether better adapted for 

 rambling afield than most Tenthredinidae. Their bodies 

 are harder, their wings stronger, and their speed, strength, 

 and often somewhat formidable appearance may carry 

 them safely over areas which it w r ould be dangerous for a 

 Tenthredinid to enter. It may be remarked also that the 

 Siricidae whose distributions are most " discontinuous," 

 belong to a group (Oryssus, Ojphrynojpus, etc.) whose species 

 are rarities everywhere, and may probably be approaching 

 extinction. It is still represented by at least one or two 

 species in all Regions, and there can be little doubt that 

 it was once a flourishing Family. Most of its characters 

 appear to be exceedingly primitive, those of the ovipositor, 

 etc., being remarkably " generalised " ; others, however — 



