1918] Crampton—Study of Terga and Wing Bases 11 
1914,. Crampton—On the Misuse of Terms, etc. Jour. N. Y. 
Ent. Soc. 22, p. 248—(Parategula shown in Fig. 4). 
1916. Crampton—Phylogenetic Origin of the Wings, etc.  Tbid., 
24, p. 1—(Tergum and wing base of Plecopteron figured). 
1917. Pantel—A proposito de un Anisolabis alado. Mem. 
Real Acad. Ciencias y Artes, 14, p. 3—(Numerous figures of 
terga and wing bases of Dermaptera). 
1908. Snodgrass—A Comparative Study of the Thorax in Orth- 
optera, Euplexoptera, and Coleoptera. Proc. Ent. Soc. 
Wash., 9, p. 95—(Terga and wing bases of Dermaptera and 
Coleoptera figured). 
1909. . Snodgrass—The Thorax of Insects and the Articulation of 
the Wings. Proc. U. S. Nat. Museum, 36, p. 511—(Terga 
and wing bases of Plecoptera, Dermaptera, and Coleoptera 
figured). 
ABBREVIATIONS. 
(The subscripts 2 and 3 denote mesothoracic and metathoracic 
structures respectively.) 
a...Adanal process (adanale) sometimes a detached plate, but 
usually serving as a pivot for wing in movements of flight. 
abd. First abdominal tergum. 
ac ..Alacrista,or alar ridges for holding elytra in place when at rest. 
d...Myodiscus, or muscle dise. 
m ..An alar ossicle, the medipterale. 
np..An alar ossicle, the notopterale. 
p...Chitinous area possibly homologous with the parategula. 
pa. .Prealare, or prealar sclerite. 
pse . Prescutum. 
psl. . Postscutellum. 
“+ pt ..Postplica, or posterior fold of tergal region. 
ptg . Parategula? 
s...Spiracle. 
sa ..An alar ossicle, the basanale. 
ss . .Scutal suture. 
su ..Suralar process (suralare) serving as a pivot for movements of 
flight. 
t ... Region homologous with tegula? 
tg. .Tegula. 
tr ..Transcutal suture. 
