THE AMERICAN ENTOMOLOGIST. 



259 



Labrum of first 

 form of trophi in 

 Ornix inusitatu- 

 mella (after Cham- 

 bers). 



Coiiscium 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. 139.] Gracilaria or Ornix (but, 

 as they are retractile, they 

 may nevertheless exist). I 

 have seen the cast head of 

 Coriscium albaiwtella of the 

 first stage. It resembles so 

 closely that of Phyllociustis, 

 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 iniisita- 

 ticmella Cham. ; Fig. 130 that 

 Labrum of first of O. pruuivorella ; Fig. i-?i 



form of trophi in -^ o ^ 



Ornijc prunvuor- that of GracHuria robiniella 



ella (after Cham- 

 bers). 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 

 [Fig. 131.] is the labrum of Phyllocnis- 

 tis vitifoliella Cham., and 

 will answer for that of Cor- 

 iscium all>anotella\ Fig. 136, 

 Lithocolletis o ma tell a ; Fig. 

 133, Leucanthiza amphicar- 

 pea'foliclla 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 [Phyllocnis- 

 tis vitifoliella). Fig. 

 141 is the labium of the 

 first form in Phyllocnistis ; Fig. 142 that of 

 Lithocolletis guttifinitella, but will answer 

 sufficiently well for any species of the flat 

 or ornatella groups : while Fig. 139 repre- 



Labrum of Gra- 

 citnria robiniella 

 (after Chambers). 



[Fig. 133.] 



Labrum of first form in 

 Phyllocnistis vitifoliella 

 (after Chambers). 



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

 mislaid, will be given in the next number. 



r 



[Fig. 13.1.1 



\M 



L.ibrum of first form in 

 L e 11 ca n th iza a mph icar~ 

 />e(e/oliella (after Cham- 

 bers). 



There ajjpears to 



[Fig. m 



Labrum of first form in 

 Lithocolletis guttifinittl- 

 la (afler Chambers). 



sents that of L. robiniella of the cylindrical 

 group, and Fig. 140 that of Leucanthiza 

 amphicarpea'foliella. In Lithocolletis and 

 Leucanthiza the labium consists of an upper 

 and lower lobe; in Phyl- 

 locnistis it consists of a 

 single lobe. Fig. 143 is 

 the labium of Ornix 

 prunivorella Cham. 

 That of inusitatumella 

 is similar to it, but has 

 the lateral tines shorter 

 lie 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 

 Phyllocnistis is not very 

 different from that of 

 Lithocolletis and Leucanthiza. The trophi 

 of Leucanthiza do not differ essentially from 

 those of Lithocolletis. The labium in Graci- 

 laria (Fig. 144) and in Ornix 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 Ornix 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 ajj- 

 pear to be the earliest 

 or most elementary 

 form from which the 

 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. 13.5.] 



Labrum of first form in 

 Lithocolletis robiniella 

 (after Chambers). 



[Fig. 13C.] 



Labrum of Lithocolletis 

 ornatella (after Chambers). 



