NEPHOPTEEYX AB1ETELLA. 255 



To this Dr. Wood replied as follows on the 11th of 

 October, 1879 : 



" It seems to me the question you have raised as to 

 the length of the larval life of Phycis abiefella is a very 

 difficult matter. I told you all the larvse do not form 

 the round cocoons, and I think it is more especially 

 the earlier and better fed ones that do not. This is 

 in favour of your views, but again&t it is the unques- 

 tionable fact that the fall-fed larvae construct them. 

 Then, again, the insect I bred this summer occupied 

 just such another cocoon ; it deserted it in May, 

 showed no desire to eat, but at once began to construct 

 an ordinary shaped one in which to pupate. 



" The impression conveyed to my mind by these 

 facts has been, that at a comparatively recent time in 

 the history of the insect it was a two-years feeder, 

 making use of these round cocoons in the first year 

 as hibernacula; but that, although it has now become 

 a one-year feeder, the memory of the old habit is not 

 altogether lost, and is called into action perhaps by 

 the lateness of the season or want of nutritiousness in 

 the food, causing the larva to be somewhat imperfectly 

 fed. But it is an intricate question." (William 

 Buckler, October, 1879; Note Book II, 105, 130, 

 142, 146, 151, 157; and E.M.M., May, 1888, XXIY, 

 269—272.) 



Nephopteryx roborella. 

 Plate CLYIII, fig. 9. 



On the 22nd of May, 1882, I figured a larva beaten 

 from oak by the Rev. John Hellins on the 19th. 



It measured about 10 lines long, and was a trifle 

 stoutest in the middle of the body, and tapered a 

 little behind ; the back was rather flattened. The 

 head was of a roundish character, just fitting within 

 the second segment; the third and fourth segments 

 have deep wrinkles, and beyond them each of the 



