1920] Crampton — Lower Lepidoptera and Trichoptera 29 



Lepidostoma speaks of the wings of the male as "clothed with 

 scattered black 'scales' regularly placed . . . ," and some- 

 what similar "scales" occur in certain Leptocerids as well as in 

 the Sericostomatid mentioned above. It must be admitted how- 

 ever, that the "scales" of Trichoptera are not exactly like those of 

 Lepidoptera (see Kellogg, 1895, American Naturalist), though 

 their function in certain cases {e. g. androconia-like structures of 

 Mystacides wing, described by Kellogg, 1895) may be very like 

 that of the scales of Lepidoptera.^ Cummings, 1914 (Proc. Zool. 

 Soc. London, 1914, p. 461) states that "The occurrence of typical 

 unicellular scent glands at the bases of hairs in Trichoptera as well 

 as Lepidoptera is interesting, and in view of the close relationship 

 between these two orders not wholly unexpected. ... In 

 Sericostoma they (scales) occur on the maxillary palpi, a position 

 in which, I believe, they are undescribed in Lepidoptera." The 

 absence of scales from the maxillary palpi in all Lepidoptera and 

 their presence in some Trichoptera, may prove to be another 

 distinguishing feature in defining the two orders. 



From the foregoing discussion it is quite evident that the simi- 

 larity in the head capsule, the general character of the mouthparts 

 (both adult and pupal), the nature of the thoracic sclerites, the 

 wing venation and presence of a coupling apparatus of the primi- 

 tive jugo-frenate type, the general character of the terminal ab- 

 dominal structures, and the occurrence of moss-inhabiting larvae, 

 are features indicating an extremely close relationship between 

 the lowest Lepidoptera and Trichoptera, so that Comstock's 

 removing the micropterygoids from the Lepidoptera to the Tri- 

 choptera has considerable justification. On the other hand, the 

 subdivision of the mesothoracic coxa for its entire length, into 

 eucoxa "vc" and merocoxa "me" (Fig. 1) in all Lepidoptera 

 studied, and the vierely partial subdivision of the mesothoracic 

 coxa^ of all Trichoptera examined (Fig. 3 "vc" and "me"), to- 

 gether with the presence of a basicoxite "cm" (Fig. 3) marked off 

 by a downward-sweeping line of demarcation in the mesothoracic 

 coxa of all Trichoptera studied, and the absence of this type of 

 structure in all Lepidoptera examined furnish us with an appar- 



iBusck, 1914 (Proc. Ent. Soc. Washington, 16, p. 50), calls attention to the fact first observed 

 by Spuler, that if the scales are removed from the wing of a micropterygid, its surface is seen 

 to be covered with minute curved spines (like those of Trichoptera) occurring "between the 

 scales and much more numerous than these." 



