16 
Psyche 
[ March 
Order Trichoptera 
Astenophylax argus Harris (Fig. 21) 
The arolium is much like that of Panorpa and differs only 
in the curvature of the camera which is U-shaped in Asten- 
ophylax. The planta is also similar, that is, a narrow rod- 
like structure distad of the unguitractor. The basipulvilli 
are large and are located at the bases of the leathery pul- 
villi (pv) which are heavily fringed with long narrow 
scales. The claws are simple instead of pectinate and the 
median ridge is absent from the unguitractor, — two fea- 
tures in contrast to the condition in Panorpa. 
Order Lepidoptera 
Automeris io Fab. (Fig. 22) 
The claw-segment of Automeris is very similar to that of 
Astenophylax and varies only in the narrower, curved pul- 
villi and the nature of the arolium which gives evidence of 
developing a secondary lobe. The condition in many Lepid- 
optera where the arolium is lacking has not been investi- 
gated. 
This agreement between Lepidoptera and Trichoptera 
was to be expected, although such a complete resemblance 
is perhaps surprising. There are also certain features trace- 
able to Panorpa. (see Figs. 20 and 22). It is conceivable 
that some Mecopteran will be found with traces of pul- 
villi which appear to be common structures in the orders 
Lepidoptera, Trichoptera and Diptera. There can be no 
question but what the condition in Panorpa approaches that 
of the Trichoptera and Lepidoptera more closely than it 
does the Neuropteran types, except for the absence of pul- 
villi. 
Order Diptera 
Tabanidae — Tabanus atratus Fab. (Fig. 23) 
The unguitractor is broadly triangular and the pulvilli 
and basipulvilli are typical. The arolium is articulated with 
the unguifer and on the ventral surface its membrane is 
continuous with that surrounding the basipulvilli and ungui- 
tractor. This is the structure erroneously referred to as 
pulvilliform empodium; it is really an arolium. (Cramp- 
