202 LEPIDOPTERA. 



used ; c, the pupa.^ This family is of especial in- 

 terest because it contains a few genera (Antispila, 

 Heliozela, Nepticula) whose larvae have very minute 

 thoracic and no abdominal legs. The habit of mining 

 leaves and hving within the burrows has probably 

 brought about these changes in structure. The larva 

 of Phyllocnistis has not only lost the abdominal and 

 thoracic legs, but, according to Clemens, to a great 

 degree the power of motion, and, as stated by that 

 author,- it makes *' little or no voluntary movement 

 when removed from the mine, and does not retreat 

 in its mine when touched." Other allied genera have 

 also been described by the same author as having 

 similar habits and being similarly modified.^ 



In the Catalogue of Tineina by Chambers,^ Clemens 

 is also cited as mentioning the resemblance of the 

 larva of one species of Nepticula to the larva of a 

 Dipteron. Drawings of this genus and of Antispila 

 are given in the Nat. Hist, of the Tineina, Stainton, 

 Vols. I., XI. 



Among butterflies no absolutely footless larvae have 

 been found. The caterpillars of Thecla, which glide 

 rather than walk, approximate to this condition in so 

 far as they possess only the three pairs of jointed 



1 For further information, see " Insect Life," Bull. U. S. Dept. 

 Ag., Vol. II., Nos. 7, 8, 1890. 



2 Proc. Phil. Acad. Sci., 1859, p. 327. 



^ See Tineina of North America, Clemens, pp. 25, 26. Also 

 compare the description of the larva of Lithocolletis (p. 63) 

 with that of Leucanthiza (p. 85), Tischeria (p. 80), and tinally 

 Aspidisca (p. 26), and Phyllocnistis (p. 83). 



4 Bull. U. S. Geol. ami Geog. Survey, Vol. IV., Xo. i, 1878. 



