The following works which are continually quoted are referred to in the text by letters only. It is hoped all other abbreviations will explain themselves. It may be well to mention that 'SB.' and 'Dk.' stand respectively for 'Sitzungsberichte' and 'Denkschriften.'

A. M. A

Archiv fur Microskopische Anatomie, Bonn.

A. N

Archiv fur Naturgeschichte, Berlin; often cited in literature as Wiegmann's or Troschel's Archiv.

A. N. H

Annals and Magazine of Natural History (various series), London.

A. Sc. N

Annales des Sciences Naturelles, Zoological section (various series), Paris.

A. Z. Expt

Archives de Zoologie Experimentale et Generale (two series), Paris.

C. R

Comptes Rendus des Seances hebdomadaires de l'Academie des Sciences, Paris.

J. L. S

Journal of Linnean Society, Zoological section, London.

J. Z

Jenaische Zeitschrift fur Naturwissenschaft, herausgegeben von der Med. Nat. Gesellschaft zu Jena.

M. J

Morphologisches Jahrbuch, eine Zeitschrift fur Anatomie und Entwickelungsgeschichte, Leipzig.

Ph. Tr

Philosophical Transactions of the Royal Society, London.

P. R. S

Proceedings of Royal Society, London.

P. Z. S

Proceedings of Zoological Society, London.

Q. J. M

Quarterly Journal of Microscopical Science, London.

Tr. L. S

Transactions of Linnean Society (two series), London.

Tr. Z. S

Transactions of Zoological Society, London.

Z. A

Zoologischer Anzeiger, Leipzig.

Z. W. Z

Zeitschrift fur Wissenschaftliche Zoologie, Leipzig; often cited in literature as Siebold and Kolliker's Zeitschrift.