206 A Classification of Lepidopterous Lai^vse. 



Thus there appear to be two subventral tubercles, the upper poste- 

 rior, the lower anterior. 



There are two lines of specialization. The first consists in the 

 loss of all the tubercles as well as the feet, even of the thoracic ones. 

 This is seen in certain Tineids (e. g., Antispila nyssaefoliella), 

 which are adapted to living in mines between the two surfaces of a 

 leaf. The second line occurs in larvae living an exposed life. It 

 begins in the multiplication of the hairs of the tubercles and the con- 

 version of them into warts, exactly as in the Specialized Frenatae. 

 Closely following on this comes the reduction in the number of 

 tubercles. This is seen in the Pterophorid®, where tubercle i has 

 disappeared. Next we have the reduction and disap])earance of the 

 subventral tubercles, leaving but three, two above the spiracle and 

 one below. This is probably in adaption to the form of the larva, 

 which is now becoming flattened with shortening of the abdominal 

 legs. The Pyromorphidte and MegalopygidiB are in this condition. 

 Follov/ing this stage, the substigmatal tubercles (tubercles iv and v) 

 disappear, and the flattening of the ventral region reaches its ex- 

 treme. The hairs of the tubercles have also been gradually con- 

 verted into stinging spines. In the Megalopygidae they are only 

 partially converted ; but in the Eucleidae the conversion is complete, 

 and we have, finally, the highest type of the Microlepidoptera, and, 

 perhaps, the most highly modified larva of all Lepidoptera. It is 

 interesting to note that the moths of the Eucleidge are much more 

 generalized than those of several of the families which precede 

 them, while the larviB are so highly specialized. This illustrates 

 the principle to which I alluded at the beginning of this paper, that 

 specialization in the larva may be accompanied by a generalized 

 condition of the moth. It is notorious that the larvae of the Eucle- 

 idae live for an usually long period. 



Family Cossidae. 

 Zeuzera pyrina Linnfeus. 



Mr. J. Doll has kindly obtained for me some larvte of this species, 

 recently renamed Z. decipiens^ by Mr. W. F. Kirby, of the British 

 Museum, on the supposition that our species is not the same as the 

 European. The setas arise from the centre of round black spots, 

 i, ii, and iii in the normal arrangement. In front of the si)iracle is 

 a small black spot, suggesting a tubercle, but it bears no seta; iv 

 and V arise from a single spot, and below them posteriorly is vi ; 



1 Catalogue of Lepid. Heterocera, vol. I, p. 871 (1892). 



