THE AMERICAN ENTOMOLOGIST. 



■59 



Labrum of first 

 form of trophi in 

 Ornix inusitatu- 

 mella (after Cham- 

 bers). 



Labrum of first 

 form of trophi in 



el la (after Cham- 

 bers). 



Coriscium in its first stage, and cannot tell 

 whether or not it has the lateral pseudopo- 

 dia as in Phyllocnistis or not ; and I have 

 not found them in the first stage of either 

 [Fig. 129.] Gracilaria or Ornix (but, 



as they are retractile, they 

 may nevertheless exist). I 

 have seen the cast head of 

 Coriscium albanotella of the 

 first stage. It resembles so 

 closely that of Phyllocnistis, 

 that it is unnecessary to 

 figure it. In all of its subsequent stages 

 however (four), it is very closely allied 

 to Gracilaria, as also is the genus Ornix. 

 But these two genera have the labrum 

 [Fig. 130 1 of the first form very dif- 

 ferent from that of Phylloc- 

 nistis. Fig. 129 represents 

 the labrum of Ornix imisita- 

 tumella Cham. ; Fig. 130 that 

 of O. prunivorella ; Fig. 131 

 that of Gracilaria robiniella 

 Clem. The differences in 

 form of the several organs of the trophi 

 of the first form are greatest in the labrum ; 

 it assumes a greater variety of form than 

 either the mandibles or labium. Fig. 132 

 is the labrum of Phyllocnis- 

 tis vitifoliella Cham., and 

 will answer for that of Cor- 

 iscium albanotella; Fig. 136, 

 Lithocolletis ornatella ; Fig. 

 T33, Leucanthiza amphicar- 

 petvfoliella Clem.; Fig. 134, L. guttifinitella, 

 and Fig. 135, L. robiniella. Fig. 138* is the 

 mandible of Lithocolletis guttifinitella, but is 

 typical of the first form of trophi of all 

 of the genera above 

 named except Corisci- 

 um and Phyllocnistis, 

 which are represented 

 at Fig. 137 [PKyllocnis- 



Labrum of first form in ,,• -j-x t n \ x^- 



Phyllocnistis vitifoliella ^^^ Vltlfoliella). Fig. 

 (after Chambers). ^^^ -^ ^j^^ j^^j^^^ ^^ ^j^^ 



first form in Phyllocnistis ; Fig. 142 that of 

 Lithocolletis guttifinitella, but will answer 

 sufficiently well for any species of the flat 

 or orjiatella groups ; while Fig. 139 repre- 



Labrum of Gra- 

 cilaria robiniella 

 (after Chambers). 



[Fig. 132.] 



* Fig. 138, the electrotype of which has been accidentally 

 mislaid, will be given in the ne.'it number. 



sents that of L. robiniella of the cylindrical 

 group, and Fig. 140 that of Leucanthiza 

 amphicarpexfoliella. In Lithocolletis and 

 Leucanthiza the labium consists of an upper 



[Fig. 1.33.] 



Labrum of first form in 



[Fig. r?A^, 



and lower lobe; m Phyl- 

 locnistis it consists of a 

 single lobe. Fig. 143 is 

 the labium of Ornix 

 prunivorella Cham. 



That of inusitatumella L,eucanthiza amplticar- 

 peoefohella (after Cham- 



is similar to it, but has ''^'■^^• 



the lateral tines shorter. There appears to 



be considerable variation within the limits 



of each genus in the form of the labrum, 



but little in that of the labium, and still less 



in the mandibles. But 



the labrum and labium 



in each genus differ 



somewhat from those 



of the other genera, 



though the labrum of . , r <■ , <• 



° Labrum of first form in 



Phyllocnistis is not very Lithocolletis guttifinitel- 

 '' ■'la (after Chambers). 



different from that of 

 Lithocolletis and Leucanthiza. The trophi 

 of Leiicanthiza do not differ essentially from 

 those of Lithocolletis. The labium in Graci- 

 laria (Fig. 144) and in Orfiix is very similar 

 to that of Phyllocnis- 

 tis, whilst the labrum 

 differs decidedly from 

 that of all the other 

 genera ; whilst Corisci- 

 um, closely related to 

 Gracilaria and Ornix, 

 has all of its trophi 

 of the first form scarcely distinguishable 

 from those of Phyllocnistis. Lithocolletis, 

 Leucanthiza, Gracilaria and Ortiix have 

 mandibles alike (Fig. 138), and very differ- 

 ent from those of Co- 

 riscium and Phyllocnis- 

 tis (Fig. 137). On the 

 theory of evolution, 

 Phyllocnistis would ap- 

 pear to be the earliest 

 or most elementary 



form from which the Labrum of Lithocolletis 

 , , , or«rt/^//a (after Chambers). 



others may have been 

 derived. But, as presently shown, it is at 

 least as probable that all are degraded 

 from a higher form or forms, and not evolved 



[Fig. 135.; 



Labrum of first form in 

 Lithocolletis robiniella 

 (after Chambers). 



[Fig. 136 



