102 Dr. T. A. Chapman's Notes on Xylcborus disyar. 



opening, opening into the interior of the double sacculus. 

 Round this centre circle is a larger one, that in some 

 prepared specimens looks very like an ordinary spiracular 

 circle. From the centre small circle, a tracheal vessel 

 proceeds inwards. It would seem that the tracheae open 

 therefore into these sacculi, and not directly into the air, 



Fig. 4. — Spiracle of larva of A'. 

 dispar. 1. Hollow in which structure 

 lies. 2. Appears to be spiracle proper. 

 3. Sacculus outside spiracle lying flatly 

 in hollow. 4. Tracheal tube seen 

 through skin. 



Fig. 5. — Diagram of 

 subsegmentation and 

 arrangement of hairs 

 of an abdominal seg- 

 ment of larva of A'. 

 dispar. 



which must pass through the saccular walls. Probably a 

 provision against moist surroundings. 



I add a diagram of the disposition of the hairs on an 

 abdominal segment of the larva and of its subsegmenta- 

 tion. 



