266 BRITISH LEPIDOPTERA. 



the general circulation in the leaf, quickly die, so that the mine seems 

 to start from a brown dead patch in the leaf. The mine is irregular 

 in shape, long, greenish in colour, and stuffed as full of coiled frass as is 

 possible, and one is struck not only with the remarkable regularity of 

 the " coils " of frass, but is convinced that by no other means could 

 the frass have been successfully packed away. The mine presents a 

 very perfect example of those with a small transverse capacity and 

 coiled frass, the want of width being the result of the very partial 

 manner in which the parenchyma is removed. The mine is much 

 larger than that of A T . (Uxtint/uenda ; it is filled with greenish frass, and 

 begins invariably from a brown bunch of convolutions of some size 

 placed at an angle of the midrib ; whereas, the other starts from a 

 point, without any series of twists aqd turns or sign of discoloration, 

 and contains brown frass. The mine is very difficult to see, owing to 

 its retaining so nearly the colour of the leaf (Wood). Heinemann says : 

 "The mine is long, narrow and tortuous, entirely filled up with dark 

 green excrement." Theegg is laid on the undersurface near a rib (Wood). 



LARVA. The larva of X. continudla presents a well-marked 

 example of borrowed colouring, for so deep and pure a green does it 

 look in the mine, that it is hard to believe that it is in reality a rich 

 yellow. It mines with the back up, but exhibits neither the cephalic 

 ganglia nor ventral cord. It is yellow in colour, though, in xitn, it 

 looks green in consequence of the light reflected from the floor of the 

 mine. The body has no visible markings. The head is pale brown. 



COMPARISON OF THE MINES AND LARVAE OF N. CONTINUELLA AND N. 

 LUTEELLA. Like the mine of A T . dixtimjuenda, that of X. continudla 

 is a very perfect example of those mines, which have a small transverse 

 capacity and coiled frass, the want of capacity in the former depending on 

 the extreme narrowness of the mine, and in the latter upon the very 

 partial manner in which the parenchyma is removed. They can, 

 however, be readily distinguished from each other. A", continudla 

 makes a much larger mine, which is filled with greenish frass, and 

 begins invariably from a brown bunch of convolutions of some size, 

 placed at an angle of the midrib, whereas, the other starts from a 

 point without any series of twists and turns or signs of discoloration, 

 and contains brown frass. Utterly unlike in their mines, in their 

 larvae, X T . continuella and X. luteella are-closely related. J3oth larvae 

 are yellow, with pale brown heads, and no trace of either cephalic 

 ganglia or ventral cord. The larva of X. luteella may be known out 

 of the mine by the urinary tubes, but they are not dark enough to be 

 seen when the creature is in the mine. The larva of N. continudla, 

 yellow though it be. looks in situ green, and a very decided green, 

 too, in consequence of the light reflected from the floor of its mine. 

 Both species are double-brooded (Wood). 



COCOON. The cocoons (4) divide into two sets. Two of them are 

 3 mm. long and 2 mm. wide, and dark red-brown in colour ; two 

 others 2-25 mm. long and 1-5 mm. wide, and pale greyish-brown in 

 colour. In outline they are not unlike an almond, but a slight 

 concavity on one side suggests the familiar " mussel " shape of so 

 many of the cocoons of this group. There is no distinct lateral flange, 

 the upper dome-shaped surface rising direct from the edge to the 

 central point. One of the ends is distinctly broader than the other, 

 the pupa emerging from the former. The surface of the cocoon is 



