446 



Dr. E. J. Tillyard on 



Mouth-parts : — Labrum apparently with the outer margin entire, 

 slightly convex. Mandibles of normal size, not hypertrophied as in 

 Eriocrania and a number of Trichoptera; in shape somewhat 

 triangular, with a broad base carrying the condyle at its outer angle 

 and with a very strongly-formed apical tooth, sharply pointed. 

 The inner edge of this tooth, from base almost to apex, is excessively 

 finely crenulated. The two mandibles are not symmetrical, the 



Fig. 2.—Sabatinca inconcjruella Walk. Cocoon, attached to stem 

 of liverwort, (x 10-7.) 



right one carrying, about half-way from base to apex on its inner 

 margin, a much smaller tooth, between which and the large tooth 

 a small notch is formed. Correlated with this formation, there is 

 on the left mandible a slightly projecting, sharp, smooth edge, 

 which evidently works in the notch of the right mandible. By 

 this means, after the sharp teeth of the two mandibles have pierced 

 the pupal skin, it may be supposed that a kind of scissor-like action 

 is brought into play, so that the cocoon can be gradually cut or 

 torn more or less transversely to its main axis. This type of 



