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question. The designation tegula is applied to it in the Hymenoptera; 
but in the Diptera, this term would create confusion, since it is also 
applied to the posterior lobe-like appendages of the wing, in the latter 
insects. In the Lepidoptera, the shell-shaped scale is termed the 
“patagium”, but this is entirely incorrect, since the true patagium, which 
is a lobe-like structure borne on the posterior portion of the pronotum, 
is often present in the same individual in which the scale in question is 
also clearly discernible. Latreille, 1822, terms the scales, “ptery- 
godes”. The designation epaulet (from the early French writers 
Chabrier, 1822, Audouin, 1840, etc.) or the designation tegula, is 
the preferable term to apply to the structure in question. 
Pleurites. 
Beneath the wing, at its base, are the basalar plates, or the an- 
terior and posterior basalare, aba and pba. These are situated in 
front of the pleural alar fulcrum, which serves as a pivot for the wing 
in the movements of flight. Behind this fulcrum, and immediately below 
the wing are the subalar plates, or the anterior and posterior sub- 
alare asa and psa. All of these plates may be designated as alar- 
pleurites (from their intimate association with the wing in the move- 
ments of flight). Snodgrass, 1909b, terms them the paraptera, but 
this term is a synonym of tegulae. 
The principal plate of the pleural region, is the eupleuron, com- 
posed of the sclerites em, es, and pl (fig. 1) well illustrated by the 
earwig Forficula. In this plate, an infolding of the wall (i. e. an implex) 
with its external suture (the pleural suture), marks off a posterior region 
em, the epimeron. The sclerite immediately in front of the pleural 
suture, is the episternum, es. The formation of a second suture (in 
front of the episternum) marks off the sclerite /pl, or lateropleurite 
shown in its most characteristic form in the Dermaptera. As was stated 
above, the lateropleurite, episternum and epimeron together make up 
the eupleuron, or principal pleural plate, which was doubtless originally 
a simple undivided plate but later became secondarily marked off into 
the regions described above. The fusion product of this plate united 
with the sternum is usually designated as the pectus. The pleural 
plate (eupleuron) is usually connected with the sternal region by a pre- 
coxal bridge pre (precoxale) extending in front of the coxa, and also 
by a post-coxal bridge poc (postcoxale) extending behind the coxa. 
These “bridges” may occur as separate and distinct plates, not united 
with the pleural and sternal plates. 
As was mentioned above, the pleural and sternal regions may 
become united to form one continuous region, the pectus. In this fusion 
