Class INSECTA or HEXAPODA.

Sub-class A, APTERYGOTA.

Order 1. Thysanura (Bristle-tails).
      2. Collembola (Spring-tails).

Sub-class B, EXOPTERYGOTA.

Order 1. Dermaptera (Earwigs).
      2. Orthoptera (Cockroaches, Grasshoppers, Crickets).
      3. Plecoptera (Stone-flies).
      4. Isoptera (Termites or ’White Ants’).
      5. Corrodentia
         (a) Copeognatha (Book-lice).
         (b) Mallophaga (Biting-lice).
      6. Ephemeroptera (May-flies).
      7. Odonata (Dragon-flies).
      8. Thysanoptera (Thrips).
      9. Hemiptera
         (a) Heteroptera (Bugs, Pond-skaters)
         (b) Homoptera (Cicads, ‘Greenfly,’ Scales).
     10. Anoplura (Lice).

Sub-class C, ENDOPTERYGOTA.

Order 1. Neuroptera (Alder-flies, Ant-lions, Lacewings).
      2. Coleoptera (Beetles).
      3. Mecaptera (Scorpion-flies).
      4. Trichoptera (Caddis-flies).
      5. Lepidoptera (Moths and Butterflies).
      6. Diptera (Two-winged flies)
         (a) Orthorrhapha (Crane-flies, Midges, Gnats)
         (b) Cyclorrhapha (Hover-flies, House-flies, Bot-flies, &c).
      7. Siphonaptera (Fleas).
      8. Hymenoptera
         (a) Symphyta (Saw-flies)
         (b) Apocrita (Gall-flies, Ichneumon-flies, Wasps, Bees, Ants).

TABLE OF GEOLOGICAL SYSTEMS

These names, given by geologists to the various divisions of rocks, as indicated by the fossils entombed in them, are arranged in ‘descending’ order, the more recent formations above, the more ancient below, as newer deposits necessarily lie over older beds.

CALNOZOIC OR TERTIARY GROUP.

Pleistocene. 
Pliocene. 
Miocene. 
Eocene.

MESOZOIC OR SECONDARY GROUP.

Cretaceous. 
Jurassic. 
Triassic.

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.

A. GENERAL WORKS.

1909.  C. Boerner.  Die Verwandlungen der Insekten. Sitzb. d.  Gesellsch.
          naturforsch.  Freunde, Berlin.