TPJE CANADIAN ENTOMOLOGIST. 155 



are similar to structures possessed by LithocoUetis, Graciiaria, and other 

 genera, the larva of which in their early stages have mouth parts of the 

 " first " form. A peculiarity of this " first " form is that, owing to the 

 structure of the mouth parts, the larva possessing them can not feed down 

 into the parenchyma like a larva having trophi of the " ordinary " form, 

 but can only eat in the plane in which the larva lies, consuming a few of 

 the cells of the parenchyma lying next to the cuticle, and leaving all 

 beneath it uneaten ; while a larva with the "ordinary " form eats out the 

 whole parenchyma, or at least eats down into it. A glance at the mine 

 of B. a7nbrosicefoliella was therefore sufficient to show me that my sugges- 

 tion as to the group to which Biiccidatrix belongs was unfounded ; the 

 entire parenchyma was eaten out, and therefore the trophi were of the 

 " second " form, and different from those of Lithocol/etis, etc. On closer 

 inspection, however, the earliest part of the mine did not appear to have 

 all of the parenchyma eaten out. Still it did not have the appearance of 

 a mine of a larva having the " first " form of trophi ; the eaten portion 

 did not all lie close to the cuticle, but the parenchyma was irregularly 

 eaten into — sometimes eaten almost through — in a way that could not be 

 done by a larva with the "first" form of trophi, but which might have 

 been done by a very young and small larva with trophi of the " second " 

 form, and dissection showed that this was the truth of the matter. The 

 larva never has trophi of the " first " form in any stage. 



But among larvae having trophi of the " second " form, there are sub- 

 groups, each of which presents important differences from the others in 

 the structure of the different organs. Thus, so far as I have examined, all 

 the larvje of Rhopalocera have trophi differing in some respects from those 

 of Heterocera, except that the larva of the Tineid, Plutella cruciferarum, 

 has larval trophi resembling those of the Skippers. The Attacidae again 

 form a sub-group. All of the other Heterocera again, except some of the 

 Tineids to be presently mentioned, form another sub-group. These 

 " other Tineids " comprise Ceviiosioitia^ which stands alone ; Tischeria, 

 which also stands alone in some respects, whilst in others it resembles' 

 Bedellia^ Antispila, Aspidisca and some others which are more or less 

 similar to them, though differing from them in some respects, and among 

 these is Nepticula. All of these I class in a single sub-group of larvse. 

 The larval trophi oi Bucculatrix more nearly resemble those of Nepticula 

 than any of the others. Mr. Stainton (not mentioning the larval trophi) 

 has already written of Bucculatrix : " This genus ofiers several points of 



