4 
Psyche 
[ March 
these structures but wherever such parts are found they are 
called basipulvilli in this paper. 
Camera. (Bugel, or bow of Arnhart) . Camera was 
originally applied to the curved narrow sclerite supporting 
the paired lobes of the arolium in Hymenoptera (MacGil- 
livray). It is herein also used to designate the evident ho- 
mologue in Trichoptera, Lepidoptera and Mecoptera. 
Distitarsus. (onychium, digitus, ungula, etc.). The dis- 
tal tarsal segment. 
Empodium. (onychium). This term has been used for 
a variety of structures. Crampton (1923) finds that it 
should be restricted to a process of the unguitractor as 
found in Asilid Diptera and other orders. Hayes and 
Kearns (1934) accept this view and apply the term in their 
work on Coleoptera. Empodium is often used erroneously 
to refer to a pulvillus. 
Flexor membranes. These are the membranous areas be- 
neath the claws which apparently serve to transfer the ten- 
sion of the apodeme on the unguitractor to the claws thus 
forcing them downwards. They are the areas from which, 
it has been suggested, the puvilli may have developed. 
Gleitrinne or Gleitflache (de Meijere). A prolongation 
of the ventral wall of the distitarsus. It is especially devel- 
oped in Odonata and in some Coleoptera where it extends 
forward between the claws. 
Onychium. This term has been used in such a variety of 
ways that it appears impossible to define it satisfactorily 
and therefore is not used in this paper. 
Orbicula. In Hymenoptera, a small dorsal sclerite at 
the base of the arolium and distad of the unguifer. The 
orbicula is quite variable as to size and shape in this order 
and may be of taxonomic value. 
Parempodia. (paronychia). Bristle-like appendages of 
the empodium. (Coleoptera and Hemiptera). 
Planta. As used by Snodgrass, Crampton and MacGil- 
livray planta applies only to the sole of the foot (typically 
in Hymenoptera and Orthoptera). However, the examples 
