Art. VI.—A Revision of the Classification of New Zealand Caradrinina. By E. Meyrick, B.A., F.R.S. [Read before the Wellington Philosophical Society, 4th October, 1911.] I have here revised the genera of Caradrinina occurring in New Zealand, taking into consideration the large amount of work done in the group of late years, especially by Professor J. B. Smith and Sir George Hampson. Both these authors have done admirable work in the careful investigation of structural characters, but in my judgment both have made too many genera, and have thus been led in some cases to rely upon points of distinction that are indefinite, slight, unimportant, unnatural, or even illusive and imaginary; and Sir George Hampson has unfortunately adopted a principle of generic nomenclature which I believe is not now held by any other leading lepidopterists, and is never likely to meet with general acceptance. It will be well, therefore, to begin by making some general remarks explanatory of my own principles and practice in these two subjects. In the matter of generic nomenclature I hold as follows:— (1.) A generic name is void if published without description. Hampson agrees, but there are writers who do not. The names of Hübner's Tentamen are therefore void. (2.) Where an original genus included more than one species, and the author has not in any way expressed which species was typical, later writers can limit the meaning of the genus at pleasure by expressed intention (accidental limitation by casual mention has no effect), such limitations taking effect in order of priority. Hampson assumes the first species of those mentioned by the original author to be the type, which is certainly simple, but has no other justification whatever, and it would be equally simple to assume the last. (3.) Fifty years' use in a particular sense establishes a title, and bars claim of priority. On these principles a reasonable and legitimate use is obtained without much disturbance of recognized nomenclature. As to the characterization of genera, no doubt the subject is a very difficult one, and there will always be room for much difference of opinion. But a genus must represent a definite section of a branch of the genealogical tree; it must not be made up of two sections tied together, or it will be unnatural, and, whilst it is certainly not always possible to define absolutely the distinction between two genera, an author must have structural grounds for referring any species to one or other, or the genera will be impracticable. A genus must be geographically consistent: it must have originated in one place only, and have spread thence to other regions, and its geographical distribution should not be incongruous; if it is, the supposed genus should be regarded with suspicion. Closely allied species must not be placed in genera regarded as phylogenetically remote. The value of a character for generic definition can only be determined practically; in one set of insects a particular character may be fixed and sufficient for generic and even family limitation, and in another the very same