It must be conceded that there is a want of correspondence between authors as to the generic names employed in the Noctuidœ; perhaps a greater than in other families of Lepidoptera. The main cause appears to lie in the two systems of classification. The old system, under which the species were assorted into genera from their superficial characters, found its highest expression in the works of Guenée. The new system, commenced by Stephens and Lederer, deals with the ultimate structure of certain parts, and is yet working out its results in the direction which all systems must pursue, that of perfectly reflecting in our books the order which obtains in nature itself. To this end the new system must extend itself, and is extending itself, witness the work of Packard and Dyar, to a study of the insect in all its stages. Here a narrow insistence on any one character must defeat the general aim.