26 THE entomologist's recokd. 



olive-brown beneath, the head has much black, and the black 

 tufts on the back are very strong, rising above the level of the 

 yellow hairs, especially are they strong on 5.7.8.9 and 12. 



I have had the white form with a good deal of chocolate 

 marking of the skin, and the yellow form tolerably free from it ; 

 whilst the degree of development of the black tufts of the con- 

 joined anterior trapezoidals varies very much. 



I have not mentioned yet, as I desire to do so with especial 

 emphasis, the peculiar manner in which the long hairs, after 

 being bent down parallel to the larval surface, are arranged. 

 This is exactly as if they had been brushed smoothly, but the 

 remarkable part of the arrangement is that they are always 

 brushed forwards on the right side, and backwards on the left side. 

 So that we have here an instance of bilateral asymmetry, 

 which is certainly extremely rare throughout all insects. In 

 the white form the brushing is generally most smooth and 

 perfect, in the yellow one there is sometimes a little roughness. 



When ready to spin, and some hours before it moves off in 

 search of a site for its cocoon, a change of tint occurs, the skin 

 becomes a dirty olive and the hairs nearly black, except their 

 extreme tips, which change colour but little. The appearance 

 is as if the larva had been well smoked. The larva will some- 

 times eat a whole leaf whilst the change is taking place. I 

 have had strigosa eating several days after the similar change 

 that occurs in that species had begun, but this year strigosa 

 began to excavate within a couple of hours of the first change 

 of tint being noticed, in every instance in which the observa- 

 tion was made. 



Leporina makes its cocoon by boring a hole into rotten wood, 

 though it will adopt any suitable tube, bramble or elder pith, 

 etc., just like alni or strigosa. I once found the larva in the 

 wild state making its burrow, this was into the dead bark of an 

 alder, a most ancient tree, with hard cork-like bark nearly two 

 inches thick. A typical cocoon is made by entering a vertical 

 face of rotten wood, the whole excavation being made by the 

 larva, sometimes occupying as much time as 20 hours, and 

 always about half as long again as alni, varying of course 

 according to the material. The whole excavation may be in 

 one line, but usually when half an inch deep the burrow turns 

 downwards. The total depth is i"3 inches (35 mm.), and 0*4 

 inches (10 mm.) in diameter; the exterior opening of the 

 burrow is closed by a diaphragm of dark felt, consisting of the 

 cast hairs of the larva with a minimum of silk ; 10 mm. below 



