10 DR. BRACKENRIDGE CLEMENS' LETTERS. 



this membrane had been ruptured and closed by the larva 

 with a web of silk. Although the larva lives thus apparently 

 secure and concealed from its enemies, it is not safe from the 

 attacks of a minute Ichneumon, which had destroyed great 

 numbers, and in retaliation I constituted myself the execu- 

 tioner of many of the assassins. 



The larva is 1*5 of a line in length. The head is smaller 

 than the diameter of the first segment, capable of being par- 

 tially retracted under it, nearly colourless, except at the 

 sides and the pointed, projecting mandibles, where it becomes 

 brownish. Body almost cylindrical, tapering posteriorly? 

 very slightly coloured with green, with a crimson dorsal line, 

 attenuated from its origin on the fifth segment to the ninth, 

 where it terminates in a point between two irregular patches, 

 chrome-yellow. Another specimen I examined did not have 

 the chrome-yellow patches, but the dorsal line was present. 

 Feet, $..f... 4=14.* 



The cocoon is composed of silk, perfectly white and quite 

 densely woven, is nearly flat above, irregularly elliptical and 

 attached by a web to the sides of the fold in the leaf in which 

 it is constructed. It is not uncommon to find two in the 

 same mine attached at their extremities. 



The pupa. The cytotheca is extended over the gastro- 

 theca, the extension being occupied by the antennas, wings 

 and legs, particularly by the last pair, which appear as an 

 elongated, free spine. The cephalotheca is somewhat hooked 

 and pointed at its extremity. The colour is dark brown, the 

 cytotheca being darker coloured than the abdomen. When 

 the imago is liberated the pupa case is thrust through the 

 cocoon and internal epidermis, and fixed in the cocoon by 

 means of the minute hooks or spines on the dorsum of the 

 pupa. 



The perfect insect. The first imago appeared on the 

 20th of October, and the brood continues to appear for about 



* I should perhaps explain that in this formula, which I am in the hahit of 

 using in my note-book, the dots represent footless segments of the body, and 

 the figures segments having feet, together with their number. B. C. 



