158 THE CANADIAN ENTOMOLOGIST. 



be covered by it, and for some little distance around it) reaches at length, 

 we will say, the point a, fig. i, when it is ready to begin the reticulated 

 work. Working backwards, the head is now drawn back and a little out 

 to « 3 ; the claw of the fore foot is here applied to the thread (which has 

 no elasticity, or very little, and which hardens the instant it is fairly out of 

 the spinneret) ; the head is drawn back along the line towards a, as far as 

 a 2, where it leaves the hardened thread, using the claw again, and passes 

 obliquely down and forwards again to the foot of the second rib at c, where 

 it is attached to the floor, and the thread again bent on the claw, is 

 retracted a little upwards nearly parallel to the line a and a 3, to the point 

 ^ in the figure, when, again bent on the claw, it is carried forward (adjoin- 

 ing the newly spun thread) to the point e, where it leaves the thread (just 

 as it did at « 2), and passes obliquely forwards again to the foot of the 

 third rib at _/, and this is repeated until the spinneret arrives at the point 

 g at the base of the other side of the cocoon. It is then carried along 

 the floor of the cocoon back to the point a 2, then it is again retracted to 

 the point a 4, where it is bent on the claw and advanced again to a 3. In 

 retracting the head from a to « 3, a single thread is left; returning it to a 2 

 adds another thread along that part ; from a 2 \.o c there is only a single 

 thread ; retracting it to d leaves a single thread of course, while advancing 

 it to e leaves another that far, and the thread leaves the rib, being carried 

 to f, as above stated. Thus the base or beginning of each rib (at a and 

 <r, etc.) would consist only of a single thread, but while the spinneret is 

 there it is passed severa,l times up and down that part, and the thread is 

 thus strengthened, and sometimes while at work on the reticulated net, the 

 larva, on reaching the floor, would pass its spinneret over it in various 

 directions, advancing under it up to its very beginning, thickening the 

 floor, and fastening the attachments of the ribs to it, and sometimes 

 retiring and entirely leaving the net-work so far that I thought it had left 

 it finally ; but it always returned, and continued its work on the reticulated 

 frame which, as before stated, forms at first only the outer covering of the 

 true cocoon. Hitherto the larva has been building in front of, around and 

 over its head, gradually retiring as the work advanced towards it ; there- 

 fore to make a line in one of the ribs it would retract its head, while to 

 double the line it would advance its head or spinneret. Each of the 

 obliquely transverse lines was permitted to sag down between the ribs and 

 was long enough to do so by its own weight. To make each line in a rib 

 the head was retracted the distance between three transverse lines, and 



