1967] 
Emerson — Cretaceous Insects 
279 
the inner margin of the wing. Some of these characters are shared 
with some genera of other subfamilies, but the combination does not 
fit any presently known subfamily of the Hodotermitidae. 
The Termopsinae (Emerson, 1933, figs. 13, 30, 40) has a pro- 
portionately narrower area occupied by Rs in the outer portion of 
the wing; the length of the wing is considerably larger in all known 
species ; the length of the forewing from the costal end of the humeral 
suture is about the same as or is shorter than the length of the fore- 
wing from the inner end of the humeral suture; Rs is roughly 
parallel to the costal margin; M is closer to Cu than to Rs in the 
middle of the wing; and the reticulations enclose smaller and more 
numerous spaces of the wing membrane. 
The Hodotermitinae (Emerson, in press) has well defined in- 
ferior branches of Rs reaching the inner margin of the wing behind 
the tip ; the humeral suture of the forewing is somewhat sinuate ; the 
length of the forewing from the costal end of the humeral suture 
is about equal to the length from the inner end of the humeral suture. 
The characteristic inferior branches of Rs and the width of the area 
occupied by Rs and its branches in the outer portion of the wing 
allow rather easy identification of this subfamily from the forewings 
alone. It should be pointed out that there is only a little difference 
in the angles of the branches of Rs in designating a branch as in- 
ferior or superior, and in some individual cases the distinction is 
somewhat arbitrary. From an evolutionary point of view, the trans- 
ition from superior to inferior branches would seem to be only a 
slight step, and some other subfamilies such as the Termopsinae, 
Porotermitinae, and Stolotermitinae have individuals that may have 
one or more inferior branches of Rs. 
The subfamily Porotermitinae with a single genus including three 
species distributed in temperate areas of southern Australia, South 
Africa, and Chili, has a fairly straight humeral suture of the forewing 
with a short curve near the costal end ; all known species of Poro- 
termes are much larger than Cretatermes) the wing is proportionately 
longer compared to its width in most species of Porotermes except 
P. adamsoni in which the proportions are similar to those in Creta- 
termes ; Rs is closely parallel to the costal margin throughout the 
length of the wing; the superior branches of Rs are thick and strong 
and are not secondarily branched as in the Cretatermitinae ; the main 
stem of Rs is as strong as the superior branches, but from 0-3 in- 
ferior branches are as weak as M and reach the inner border of the 
wing below the tip ; M is about half way between Rs and Cu in the 
