Palaeozoic or Primary Group.
- Permian.
- Carboniferous.
- Devonian.
- Silurian.
- Cambrian.
BIBLIOGRAPHY
The following list of some books and papers, referred to in this little volume or of especial service to the author in its preparation, is needless to say very far from exhaustive. To save space, titles are often abbreviated. Most of the works in the general list (A) contain extensive lists of literature on insects and their transformations, these should be consulted by the serious student.