1973] 
Roth — Blattaria 
347 
Some genera of Perisphaeriincie have a characteristic tooth (Figs. 
232, 235, 270) on each side underneath the pronotum into which 
the apex of the tegmina fit. Princis (i960) and Beier (1961) used 
this structure as a characteristic of Derocalymminae and Derocalym- 
mini, respectively. The shape of the tooth may have value as a 
species character (cf. Figs. 232 and 235). 
Shelford (1908) summarized Saussure and Zehntner’s (1895) 
analysis of the evolution of the form of the pronotum in the Peri- 
sphaeriinae. The complex type of the pronotum of genera such as 
Pilema and Cyrtotria appear to have evolved from a more simple 
form. Pilema thoracica has been found in family groups of a female 
and nymphs in round holes in the ground about 6 inches in depth. 
Shelford suggests that the shovel-like pronotum of Pilema is prob- 
ably used for digging and evolved as a result of a change to this 
habitat. Derocalymma spp. live under heavy stones and their flat- 
tened form would enable them to crawl through narrow crevices for 
security from predators. Some species of Cyrtotria also have the 
pronotum adapted for digging, but others haven’t; nothing is known 
of the habits of this genus. The Bantua pronotum is intermediate 
in structure between Cyrtotria and Derocalymma , but nothing is 
known of the genus other than it has been collected under a log. 
Shelford suggests that the Derocalymma form originated from a form 
like Pilema evolving through a Bantua - like stage. 
Summary 
Based on male genitalia, 1 1 genera of Perisphaeriinae are placed 
in 4 tribes as follows : 
1. Perisphaeriini : Perisphaeria , Blepharodera , Pilema , Hostilia, 
Bantua , and Cyrtotria . 
2. Zuluiini : Zuluia. 
3. Derocalymmini : Derocalymma. 
4. Perisphaerini : Perisphaerus, Pseudo glomeris, and Trichoblatta. 
Acknowledgements 
I thank the following for the loan of museum specimens : Dr. 
David Rentz, Academy of Natural Sciences of Philadelphia; Dr. 
David Ragge, British Museum (Natural History) ; Dr. Karl Prin- 
cis, Zoological Institute, Lund, Sweden; Dr. M. W. R. de V. 
Graham, Hope Department Entomology, Oxford, England ; Dr. 
Howard Evans, formerly at the Museum of Comparative Zoology, 
Harvard University; Dr. S. L. Tuxen, Zoological Museum, Copen- 
