Two species of Periplaneta have been introduced into Europe. These are—
1. P. orientalis (Common Cockroach, Black Beetle). Wing-covers and wings not reaching the end of the abdomen in the male; rudimentary in the female.
2. P. americana (American Cockroach). Wing-covers and wings longer than the body in both sexes.
CHAPTER III.
The Natural History of the Cockroach.
SPECIAL REFERENCES.
Hummel. Essais Entomologiques, No. 1 (1821).