comparatively little value. To this may be added, that the caterpillars are often difficult to discover, owing to the nature of their haunts, many of them living in the interior of trees, within the substance of herbaceous vegetables, in fruits, &c. But the want of this knowledge, from whatsoever causes it may arise, has hitherto been a principal cause, and will probably long continue to be so, of preventing a natural arrangement of this tribe being effected; and the observation of Latreille will in all likelihood long continue to be applicable,—"Nepotes nostri methodum optimam soli confident."
Before referring to a few of the principal methods in which it has been proposed to arrange the nocturnal Lepidoptera, it will be of advantage to take a slight glance at some of those authors who have contributed most to extend our knowledge of exotic species, and from whose works the materials must be principally derived to form the basis of these arrangements.
The works relating to the nocturnal Lepidoptera of Europe are numerous and valuable. One of the most extensive and useful is the "Die Schmetterling von Europa," by Ochsenheimer and Treitschke, in 14 vols. 8vo. Leipzig, 1807—34. Godart has described the species indigenous to France; Duponchel has continued the work, and given an Iconography of the Caterpillars (Paris, 1832, 8vo.). Hubner, Dennis and Schiffermüller, Boisduval, and many others, have likewise made valuable contributions to the subject, in reference to its relations
