MOKGAN HEBARD 
421 
Excellent figures of this insect are given by Bormans in the 
Biologia, as S. nigrma, plate I, fig. 11 being the dorsal aspect of 
the male, fig. 12 showing further error by that author, as it is, in 
fact, an excellent outline of the ventral aspect of the pygidium 
and forceps of the same sex, though stated to be of the female. 
Borelli has pointed out this association in part, describing the 
male and giving further characters for the female, in addition to 
a full comparison with P. nigrina (Stal).i^ In this connection, 
we would remark that, in the series before us, the antennae are 
uniform in coloration or have the proximal joints only slightly 
darkened. 
Never, in our experience, has a series of the same species shown 
more startling variation than the present. Some specimens are 
tremendously larger than others. The normal coloration is, head, 
pronotum, tegmina, wings and dorsal surface of abdomen to 
ultimate segment, shining blackish, the ultimate segment, pygid- 
ium and forceps shining ferruginous; often the contrast between 
these colors is less decided and, in one specimen, the general 
coloration is prouts brown, with ultimate dorsal abdominal seg- 
ment, pygidium and forceps slightly paler. The male pygidium, 
however, shows the greatest individual differentiation, in the two 
larger males and one of the smaller males it has the meso-distal 
production rectangulate, slightly longer than wide (Plate XX VIII, 
figure 10), in the other smaller males it is triangular, with apex 
very briefly truncate, varying to acute, in length slightly greater 
than its proximal width. Many of the smaller males show forceps 
with contour variously somewhat simplified and with the three 
teeth on each arm reduced. In the smallest male before us the 
forceps have retained, in large part, the immature form; the 
sinistral being simple and unarmed, the dextral only weakly 
specialized and with only the median and distal tooth weakly 
developed. 
This insect is clearly one of those plastic species in which 
features of full and fixed diagnostic specific value in other related 
forms, show decided individual differences. 
Boll. Miia. Zool. Anat. Comp. Univ. Torino, xxx, no. 699, p. 3, (1915). 
TRANS. .AM. ENT. SOC., XLIII. 
