1070 The American Naturalist. [December, 
an additional primary seta (marked + in the diagram Fig. 1c). 
On the abdomen, the primary sete are present with a small addi- 
tional one behind tubercle iii (+ in Fig. 1d). I am indebted 
to Dr. Packard for the specimen. 
Hepialus humuli. Mature larva (Fig. 2). On the prothorax 
the cervical shield extends down to include the sete before 
the spiracle. No sete added to those in the first stage. On 
the last two segments the setæ are as in Stage I, without any 
of the true subprimary sete (associated with iv and marked 
* in Fig. 5), but two different ones are present (marked * in 
Fig. 2a), associated with iib. On the abdomen there are pres- 
ent, besides the primary sete, two subprimary ones (marked * 
in Fig. 2b). There are four primary sete above the spiracle, 
which is unknown in any other Lepidoptera except in the 
Microlepidopterous genus Cossus, where the fourth seta is 
probably secondary (I have not seen Stage I of Cossus) and in 
the butterfly Danais, where it occupies a different position. 
The upper subprimary seta is without an analogue so far as I 
know. The lower one I have formerly interpreted as being 
the subprimary tubercle vi of the Micros (Ann. N. Y. Acad. 
Sci., viii, 198), but this was before I had examined consider- 
able material. This interpretation is still possible, but in view 
of the fact that the tubercle is associated with vii as vi never 
is, and in view of the condition on the thorax, we cannot re- 
gard it as the homologue of vi. 
Hepialus lupinulus. Mature larva. The structure is the 
same. I cite the species to show that the characters described 
above are generic and not individual. In my example (a 
blown specimen) a number of the setz have been lost during 
the journey from Europe but the tubercles from which they 
arose can be distinguished plainly under a half inch objective 
in the proper positions. 
Superfamily MICROPTERYGIDES. 
Family Micropterygide. 
Micropteryx purpurella. Mature larva (Fig. 3). The rudi- 
mentary sete are difficult to distinguish. On the thorax I 
