1954] Cr'eighton and Gregg — Cryptocerus texanus 45 
The first person to suggest a phragmotic function for the 
major of Cryptocerus appears to have been W. M. Wheeler. 
In 1905 (5) Wheeler stated that the nest entrance of sev- 
eral colonies of Cryptocerus varians, which he had found 
in hollow twigs in the Bahamas, was always exactly the 
size and shape of the cephalic disc of the major. Wheeler 
made no claim that the major blocks the nest entrance with 
its head, but the implication that it does so was clear and 
this seems to have been the basis for later views expressed 
by Wheeler in 1910 (6) and by Emery in 1922 (7) that the 
major of Cryptocerus is probably phragmotic. But no 
Figure 2. Dorsal view of the head of the minor of Cryptocerus texmius. 
Drawn to the same scale as figure 1, a. 
positive statement was made on this point until 1942. In 
that year a posthumous paper by Wheeler (8) which had 
been prepared for publication by Dr. Joseph Bequaert, 
definitely made such a claim in the case of Cryptocerus 
pallens (the variety porrasi) and C. setidifer. The state- 
ment concerning pallens is as follows : 
“Its habits are similar to those of Colobopsis. The ellip- 
tical nest entrance is guarded by one of the soldiers which 
occludes the orifice with its disc-shaped cephalic disc just 
as the Colobopsis soldier uses the truncated anterior sur- 
