1969] 
Roth — Genitalia of Blattaria 
247 
203) in that all of the spines bordering the prepuce are relatively 
large and arise from a well defined sclerotized margin; the shapes of 
the preputial spines also differ between these 2 specimens. 
4. Blaberus sp. D (Fig. 208). — This is a species determined by 
Hebard as B. giganteus (from French Guiana) but its genitalia 
(Fig. 214) are that of a member of the Brasilianus Group. The 
truncate elevations on the left side of the prepuce are small and some- 
what like those of colosseus , but the other spines are greatly reduced 
in size and number. This specimen is probably colosseus (though 
it is somewhat broader and more intensely colored than colosseus from 
Trinidad and Mexico, (cf. Figs. 112-115) in which the preputial 
spines have been greatly reduced (cf. Figs. 116-129). 
5. Blaberus sp. E (Fig. 209). — This specimen is close to gigan- 
teus but is more slender and its general coloration is very pale. Its 
genitalia (Fig. 215) are massive and there are more rows of prepu- 
tial spines than are usually found in giganteus (Figs. 28-40). 
Distribution. — The species of Blaberus are almost entirely neo- 
tropical (Table 1). Four of the 5 species of the Brasilianus Group 
are restricted to South America; colosseus is more widely distributed 
and occurs in Mexico, Central and South America. Members of the 
Giganteus and A tropos Groups are found in Central and South 
America, and a few species occur in the West Indies, southern Florida, 
and Mexico. 
Evolution of the aedeagus and prepuce. — I believe that the prepuce 
of Giganteus Group males which lack truncate elevations and have 
relatively simple, small preputial spines is the most primitive of the 
3 groups of Blaberus. However, though the preputial spines are 
small they may vary in shape (Fig. 216) and some spines are rem- 
iniscent of those found in the Brasilianus and A tropos Groups. A 
Giganteus Grouplike form could have given rise to individuals of 
both the other 2 groups. The preputial spines of the Brasilianus 
Group are often numerous and may occur in multiple rows (e.g., 
Figs. 88, 90) like some individuals of the Giganteus Group (e.g., 
Figs. 36, 47, 215). In both the Brasilianus and A tropos Groups, the 
anterior elevations of the prepuce on the left side probably evolved 
from the left tumorlike outgrowth of a Giganteus Grouplike form. 
However, in the Brasilianus Group, the anterior elevations on the 
left and right sides do not differ greatly in size whereas there is a 
marked size difference between the elevations on the two sides in the 
mens from a laboratory culture. (Scale for pronotum [see Fig. 224] = 
5 mm.; scale for genitalia [see Fig. 218] = 0.5 mm). 
