1963] 
Evans — Cephalonomia 
59 
is, however, much variation in both these forms, so that in one sub- 
apterous female (from Douglas Co., Ore.) this ratio is the same 
(.71) as in one of the micropterous females (Santa Cruz Co., Calif.). 
However, there is considerable difference in wing length between these 
two specimens. 
As compared to the subapterous females, the apterous females have 
a slightly smaller mean size, a mean head width/length ratio of .64, 
the eyes smaller and the ocelli so small they cannot be clearly dis- 
cerned in many specimens. The wings are, of course, completely ab- 
sent, although the tegulae are of nearly normal size. The line sepa- 
rating the mesoscutum and scutellum is very weak, the continuation 
of a trend begun in the subapterous females. 
It may have been noted that there are, for most forms, fewer speci- 
mens indicated in Figures 1 and 2 than are listed in Table 1. This is 
a result of the fact that while wing length could be determined for 
all specimens, some specimens had the head missing or distorted to 
such an extent that accurate measurements could not be made. Also, 
not all specimens were measured in samples of one form from one 
locality of more than twenty. 
Discussion. — That polymorphism for wing length occurs in both 
sexes of Cephalonomia perpusilla is not in itself surprising, for several 
different patterns of polymorphism are known to occur in this section 
of the family Bethylidae. That modifications in head shape and in 
size of the eyes and ocelli accompany modifications in wing length is 
also not surprising, since this has been reported for several polymorphic 
bethylids, and most aculeate Hymenoptera which are wingless also 
exhibit reduction in eye size and loss of the ocelli (e.g., female Mutil- 
lidae). It should be pointed out that the changes in head shape are 
not merely the result of decreased area and convexity of the eyes. In 
alate forms the whole side of the head is more bulging, presumably 
reflecting the much larger size of the optic areas of the brain, as com- 
pared to wingless and short-winged individuals. The apterous and 
short-winged forms of Cephalonomia perpusilla show only very slight 
reduction in thoracic structure, in contrast to other polymorphic species 
such as Cephalonomia gallicola and Scleroderma immigrans , in which 
the apterous individuals have the mesoscutum and scutellum com- 
pletely fused and the tegulae absent. 
What is unusual in Cephalonomia perpusilla is the presence of four 
distinct types of females. Although the two types with small wings 
differ only slightly in wing length, they nevertheless differ distinctly in 
head characters. The micropterous females are basically “alate” with 
