32 THE ENTOMOLOGIST. 



hard, smooth silk, corresponding with the surrounding portion 

 of the tunnel so exactly that it almost escapes detection. When 

 this lid is removed a long perpendicular shaft is disclosed, 

 which runs down the middle of the tree to a depth of fourteen 

 or sixteen inches, and is about six lines in diameter ; at the 

 bottom of this the elongate virescens pupa sleeps quietly and 

 securely in an upright position, the old larval skin forming a 

 soft support for the terminal segment of the pupa to rest on. 

 The upper end of this vertical shaft is lined with silk, which 

 forms a framework on which the trap-door rests when it is 

 closed ; the lid itself, being of a larger size than the orifice, 

 which it covers, causes it to be extremely difficult, if not im- 

 possible, to open from the exterior, especially when it fits down 

 very closely, which is nearly always the case as long as the 

 insect remains in its burrow. The object of this most ingenious 

 contrivance is in all probability to prevent the ingress of insects ; 

 Blattse, slugs, spiders, and immature "wetas" (Hemideina) are 

 frequently found in both central and lateral tunnels, but they 

 are quite unable to pass the trap-door, and are most likely 

 entirely ignorant of the existence of the vertical burrow. When 

 the pupa has left its dwelling it becomes the permanent home of 

 these animals and many others ; I have on several occasions 

 found a small orthopterous insect (Lihanasa (?) macuUfrons) in 

 the vertical portion of deserted galleries, which has very long 

 antennae, and is agile in the extreme, leaping out of sight if 

 possible the moment the tunnel is opened ; it is a most graceful 

 little insect, and I have never discovered it in any other situation, 

 so conclude that this is its normal habitat. 



The galleries of different individual larvffi are all wonderfully 

 alike, the only differences observable being in the length of the 

 perpendicular shaft and direction of the horizontal burrow, 

 which is sometimes curved. These variations are usually caused 

 by the presence of other tunnels in the tree, which the larva 

 invariably avoids, although how the insect can ascertain that he 

 is approaching another tunnel, before he actually reaches it, I 

 cannot understand ; I have never known a single instance when 

 a larva has allowed his tunnel to communicate with a neighbouring 

 one, whether inhabited or otherwise. 



The caterpillar, when full-grown, is of considerable size, 

 measuring from twenty-eight to thirty lines or more in length ; 



