19 lo] A Structural Study of Some Caterpillars 123 



to be well-developed, the maxilla with stipes, palpifer and sub- 

 galea sometimes separately chitinized, the submenta not widely 

 separated, or even in contact, (Fig. 137). Setae of mentum rather 

 nearer the base than is typical of the Macrolepidoptera. 



There is never secondary hair on the head, and secondary and 

 tufted hair on the body only in the Pterophoridae. 



Thorax with cervical shield well developed — in the lower forms 

 with additional sclerites ventrally and laterally, which reach their 

 greatest development in Adela (Fig. 6). The true legs are 

 absent in Nepticula, replaced by patches of enlarged granulations 

 similar to those representing the prolegs. 



Abdomen usually with anal plate only, but with two dorsal 

 and two ventral plates on each segment in Incurvaria. Setae 

 i and ii well separated except in the Pterophoridae, iv and v 

 approximated, except in Yponomeuta, where they are distant and 

 iv is higher than v, they are usually on a single tubercle, and iv 

 may be much reduced. vii is quite variable, most often in the 

 Tortricidae the setae form an oblique line, while in the Tineina 

 the middle one is anterior. In the Pterophoridae, Thyris, and 

 Simaethis they lie, not on the leg, but on a plate at its base. 

 Adela and Incurvaria are somewhat different (Figs. 34 and 35). 

 via lies on the anterior side of the leg in Adela and Incurvaria. 

 On the ninth abdominal segment setae ii are both on a single 

 median tubercle in the Tortricidae, but in the others they are 

 distinct, and often distant. 



The hooks of the prolegs in the Pyralididae and Tortricidae 

 are oftenest in a complete circle, alternately of two or three 

 lengths. They are similar in Thyris, Endrosis and Depressaria. 

 Most Tineidae, as well as Phalonia and Orneodes, have but a single 

 length. In Gracilaria there is half of a second band (Fig. 7). 

 Adela has two areas of minute hooks, grading into the granula- 

 tions, which in Incurvaria are reduced to a single transverse row\ 

 Yponomeuta has three or four complete circles of hooks. Nepticu- 

 la would appear to have the hooks replaced by a vague area of 

 enlarged conical granulations. In Panorpa, there is such an area 

 of enlarged, but setiform granulations, on the posterior side of 

 each of the slender prolegs.* 



Tineola resembles Solenobia in its head and ventral prolegs, 

 but its anal prolegs are normal. 



*I am indebted to Dr. E. P. Felt and Prof. J. H. Comstock for the loan of this specimen from 

 the Cornell University collection. 



