66 
Psyche 
[April 
of the roach (Fig. 16) are probably secondarily-formed areas 
demarked by a rather faint suture pus, with its corresponding 
internal ridge epn2 of Fig. 13. These structures are extremely 
faint in the metanotum (Fig. 16). 
The scutellum of the mesothorax sl2 is greatly elongated 
and extends to the prescutal area psc of Fig. 16. In the meta- 
thorax, however, the scutellum slS is shorter and a suture-like 
structure mds of Fig. 16 connects it with the prescutal region. 
The scutellum sl2 (Fig. 16) is a demarked area of the eunotum 
bounded laterally by the scutellar sutures sis with their corres- 
ponding internl ridges etc., labelled esl2 in Fig. 13 
Behind the scutellum sl2 (Fig. 16) is the posttergite pot, 
which is formed by a posterior fold, or reduplication, of the 
wing-bearing plate, or eunotum. Behind this are the post- 
scutellar plates psl (Fig. 16), which encroach upon the mem- 
branous region, in other insects, and finally incorporate the 
marginal region pm, in front of the phragmal pits ppt, to form 
the large postscutellum of higher insects, in which the post- 
scutellum may appear to bear the phragma. The postscutellum 
of the roach is but feebly developed and is represented by the 
small plates bearing the label psl in Fig. 16. These plates are 
formed behind the wing-bearing plate, or eunotum, whose post, 
erior margin is continuous with the posterior margin of the wing. 
In the eunotum, or wing-bearing plate, the scutum sc (Fig. 
16) is very large and it occupies the greater part of the eunotum. 
It bears an anterior wing process, or suralare sur (which may be 
a lateral portion of the region pvt in some insects) , and a posterior 
wing process, or adanale ad (Figs. 16, 6 and 10), in front of 
which is an important incision ni, serving to divide the scutum 
into an anterior region and a posterior region, the latter being 
practically equivalent to the region called the parascutellum in 
other insects. The incomplete sutures extending mesad from 
the incision ni in Fig. 16, correspond in a general way to the 
transscutal sutures, dividing the scutum into an anterior and 
posterior region in certain insects. 
A tegular incision ti of Fig. 6, usually separates the prealar 
sclerite pra from the suralar sclerite sur, and the tegula tg is 
located at the mouth of the incision in most insects (Figs. 6, 10, 
