NOVEMBER, 1861. 173 



mining. The larva is very slender, of nearly uniform dia- 

 meter, terminal segments pointed, pale green, with a darker 

 green central line ; head pale brown. It should be sought 

 early in September. 



On the 14th of the month it is nearly full fed. 



4. N. Platanella. From the beginning to the middle of 

 July the blotches produced by these larvas may be found on 

 the leaves of the button-wood tree or sycamore. The blotch 

 is often extended over the early portion of the mine, so as to 

 obliterate it, and again the early portion is present, being a 

 slender line from which the blotch is formed. 



The larva is pale green and the head pale brown, and weaves 

 a cocoon of a reddish-brown colour during the latter days of 

 July. 



5. N. cratcegifoliella. The larva may be found in the 

 leaves of dwarf thorn, Cratcegus parvifolia, from the middle 

 to the latter part of July. The mine is rather a wide tract, 

 not long, most often tortuous, sometimes turned back on 

 itself and when nearly straight, with irregular edges, having 

 a narrow, contorted line of frass running through the middle 

 of it. The later half of the mine will average at least a line 

 in width. 



The larva is rather thick, bright green. One larva which 

 I observed especially mined a space of Jive lines in three days, 

 at the end of which time it was full grown. Previously it 

 was not more than half grown, and the distance mined while 

 under observation forms nearly one half the length of the 

 entire mine. The larva enters the pupa state during the 

 latter part of July. 



6. N. juglandifoliella. The larva mines the leaves of 

 black walnut from the latter part of July to the middle of 

 August. The mine is a very narrow, whitish tract, very 

 often recurved and slightly tortuous, somewhat, although 

 slightly, enlarged at its end, with a very narrow central line 



