85 



resemble very closely those made by some species of the genus 

 Tischeria (Tl heliopsisella, T. amhrosiaeella and T. tincloriella). 

 The beetle Metonius laevigatus makes a very similar nidus in 

 leaves of Desmodium, The mines of larvjB of the flat group 

 also differ both in form and color. Some, as those of X. liama- 

 dryadella^ L. cinoinnatieUa, L. coryliella, are simply roundish, 

 flat blotches ; others, as those of L. bethuneella, are smaller, 

 and liave a distinct fold of the upper cuticle across the mine ; 

 others, as L. tuhiferella and L. guttifinitella^ when only a single 

 larva is found in a mine, have more nearly the shape of the 

 track made by a drop of water in running over a leaf; others 

 have still other forms. The color of the mine depends upon 

 the species making it, and not upon the leaf in which it is 

 made. Thus L. hamadryadella and L. ciiieinnatiella mine 

 leaves of oaks of the white oak group, and their mines are 

 not dissimilar in form and size ; but the mine of L. hamadrya- 

 della is always whitish, while that of L. cmcinnatiella is dark 

 yellowish. But, as far as I have observed, the larvae of this 

 group, with few exceptions, made at first an indistinct, long, 

 crooked, narrow or linear mine, which ends in a blotch-like 

 mine. This blotch frequently spreads over and obliterates the 

 linear portion of the mine. 



With the exception of L. ornatella, which mines both sur- 

 faces of the leaves, all the larvre of the flat group mine the 

 upper surface, and all of them make what may be called blotch 

 mines, as distinguished from the tentifonn mines made, with- 

 out exception, by the larva3 of the cylindrical group. The 

 mines of every species of the cylindrical group are on the 

 under surface, except those of L. tiliaeella Cham., which are 

 always on the upper surface ; but very rarely a species which 

 habitually mines the under surface will, for some cause or 

 other, be found to have made its mine on the upper surface ; 

 yet this latter is an exceedingly rare occurrence. I give the 

 results of my own observations only. The mines of the cylin- 

 drical larvae, though always roomy or tentiform, and never 

 blotch-like, differ in size and form, in the amount of corruga- 

 tion of the cuticle, and in their position on the leaf. Many of 

 the species are more careful thau men are about the location of 



