314 Rev. F. D. Morice's Notes on Australian Sawfiies. 



they are practically colourless, and would gain no im- 

 munity from any dangers by " mimicry," etc., or formidable 

 appearance, or disguises of any kind. Against the only 

 enemies likely to assail them (Ichneumonids, carnivorous 

 beetles, centipedes, etc.) they are protected to a great 

 extent by their surroundings; and if these fail to save 

 them, they can only succumb. Disguises assumed in the 

 midst of darkness would not help them, and they cannot 

 take refuge by leaving their burrows. 



(iii) Siricid larvae, with one doubtful exception, are said 

 to be always eyeless ; whereas those of Tentkredinidae have 

 invariably a single pair of ocelli, one on each side of the head. 

 The connection of this difference with their different modes 

 of life is so obvious that it needs no comment. But it may 

 be added, that in the Cephidae eyes are not wanting, though 

 they are said to be very small. In Pamphilius, etc., they 

 are present and well-developed; and as these, though feed- 

 ing under cover, do not live in actual darkness, we have 

 every reason to suppose that eyes are useful to them. 



(d) The different bionomics of the two groups have a 

 certain effect on the structure not of their larvae only, but 

 of their imagines. In order that a Siricid egg may be intro- 

 duced into such surroundings as will suit the larvae which 

 is to issue from it, the ovipositor of the $ parent must 

 be of considerable length. Its function being simply to 

 pierce, any unnecessary breadth or thickness would render 

 it less serviceable, and yet it must be armed (at least near 

 its apex) with something in the nature of saw-teeth that 

 it may make its way through a certain amount of resistance 

 in the material to be penetrated. Accordingly the terebra 

 of a '£ Siricid is long — sometimes paradoxically long! - 

 and narrow ; its paired blades are shaped like fine needles 

 which have been more or less flattened to give them cutting 

 edges ; and these cutting edges have a few minute denticu- 

 lations just before their apices. (In the Oryssidae the whole 

 apparatus is so phenomenally slender that it might almost 

 be mistaken for a long line hair !) Even in those cases where 

 it is shortest as. for instance, in Derecyrta, Brackyxiphus 

 and certain spp. (chiefly Oriental) of Xiphydria it still 

 projects to a considerable distance beyond the dorsal apex 

 of the abdomen, and, even when at rest, cannot (as in 

 Tentkredinidae and also in Bees, Wasps, etc.) be drawn 

 backwards completely out of sight. A certain amount of 

 protection, however, is usually given to it by a modification 



