796 STUDIES IN AUSTRALIAN NEUROPTERA, vii., 



of tlie inaudible. In the living larva, the maxilUe ma}^ be seen 

 at times playing freely forwards and backwards beneath the 

 mandibles; so that it is evident that tliey have considerable free- 

 dom of movement, in spite of being designed to act as a pair of 

 complete sucking-tubes in conjunction with tliese latter. 



Whereas the groove in the mandible can be followed with ease 

 right up to tlie tip, that of the maxilla cannot be so followed, 

 and is evidently of a much more imperfect nature. Hence the 

 complete sucking-tube must be formed at least partly by pressure 

 of the two paiis of jaws, one upon the other, and not by a close 

 interlocking of parts. I have frequently seen the tips of the 

 maxillae pushed a considerable distance forward beyond the tips 

 of the mandibles; this could scarcely happen unless the fit of the 

 maxilla upon the ventral surface of the mandible were a some- 

 what loose one, seeing that the calibre of the groove varies 

 greatly from base to tip. 



When the maxilla is dissected out, it is seen to be considerably 

 swollen near the base, and to carry, below the swollen part, three 

 flat, chitinised plates, two of which ai'e broadly triangular, the 

 third very narrow. These are placed in the positions of cardo^ 

 sti^jes, and palpiger of a normal maxilla, and appear to represent 

 those three sclerites. As regards the elongated spear that forms 

 the principal part of the maxilla, this would appear to be the 

 galea. But, unless the transformation of these parts, from their 

 abnormal form in the larva to their normal form in the pupa, 

 can be followed out at metamorphosis, in such a way that there 

 can be no doubt upon the matter, I do not think that we can be 

 sure of their homologies. 



7'Ae Lahritm and Clypens (Text-fig. 5). These together form 

 one piece in the larva, indistinctly divided transversely, as shown 

 in the figure. The clypeus is covered with the usual hooked 

 hairs, set upon raised papillae The labrum is a strongly pro- 

 jecting curved lobe, carrying only three rather large hooked 

 hairs on either side. 



The Labium (Text-fig.6). This consists of an undivided tri- 

 angular basal portion, from the two anterior angles of which 

 project the five-jointed palpi. The basal joint of each palp 



