Names of authors and subjects are arranged together alphabetically.

References to species of animals described or noticed in the Journal, though to some extent distributed through the Index, are systematically catalogued under the word Zoology. The same plan is followed with Botany.

Obituary notices are collected together under Obituary.

The references under authors' names, when numerous, are sometimes alphabetized, or distributed according to subjects, but often follow the order of the volumes.

Works reviewed are mentioned under the names of their authors, and also under the word Works.

When an article is illustrated by figures or plates, the fact is noted by adding to the number of the page, the letter f.

A Supplement, (page 317,) is added, containing some omitted references.

The list of plates and wood cuts, (page 323,) is arranged according to volumes, and the page or article is mentioned which each illustrates. The numbers in this list indicate the proper order of succession in each volume, and not the numbers that may appear on the plates.