^ [Jamiaiy, 



1st skin — whitish, with black heads and brown mouth parts; 

 indistinguishable from each other. 



2nd skin — all develop a large oblong black mark on both the 

 upper and under-sides of segment two. 



3rd skin — their differences now appear: unimaculella develops 

 its black abdominal spots, though sometimes they make their appear- 

 ance in the previous skin ; semipurpurella becomes dark grey ; and 

 inconspicuclla slightly smoky, but the depth of the tint varies, and is 

 best recognised in the shrivelled skin shed at the next moult. 



4th and last skin — unimaculeUa^ the black abdominal spots and 

 the marks on segment two have disappeared ; head brown with the 

 mouth parts darker, but the posterior margins and lobes still blackish, 

 the latter appearing as a pair of dark spots under segment two ; in 

 addition to the protuberances on segment five are smaller ones on 

 segment six : semipurjntrella, still grey, but not so dark as in previous 

 skin ; head also still black, with the exception of the centre, which is 

 now brown like the mouth ; the black marks on segment two in pro- 

 gress of disintegration, and broken up into irregular black spots : 

 inconspiciiella whitish, the smoky tint quite gone ; head very pale 

 ochreous-brown, with darker mouth parts ; no trace of the black marks 

 on segment two, but in their place a slight ochreous tint. In this skin 

 it comes nearest to itmmaciihlla, but may be known, when in the mine, 

 by the absence of the pair of dark spots at the back of the head; 

 whereas, in the previous skin, its resemblance was to semipurpurella, 

 for very pallid specimens of which it has, I suspect, been mistaken by 

 collectors. The mine of semipurpurella is browner than that of either 

 of the others, and shows only a very narrow greenish border at its 

 advancing edge. 



Purpurella, an early larva like the foregoing, occupying mines 

 that differ in no respect from theirs, except in being of a greener 

 tint. It is sometimes solitary, but usually two or three are together, 

 feeding side by side in most brotherly fashion. Occasionally I have 

 seen as many as six in a mine, but they were probably the produce of 

 more than one laying. In the first skin it is greenish-white, the head 

 watery-white, with just a tinge of brown about the mouth. Little 

 change takes place in subsequent moults, and it remains to the last a 

 very delicate looking larva, of a watery-white colour ; with the head 

 concolorous, the eye-spots black, and the mouth pale brown. From 

 this absence of colour, as well as from the imperfect way in which at 

 first it removes the parenchyma, it is very difficult to see it in its 



