Hemming (1967) stated:-
Hymenitis diaphane Hübner, 1816] (as defined by fig. 3 on plate 7 in Drury's Ill. nat. Hist., which was named Papilio diaphanus in the index to volume 2 of that work after having been described but not named on page 13, that specimen having been selected by Hemming (1964, Annot. lep. (3) : 89) to represent the lectotype both of Papilio diaphanus Drury,  and of Hymenitis diaphane Hübner.
The nominal species Hymenitis diaphane was established by Hübner solely upon the basis of bibliographical references to works by previous authors. The first of these references was to Papilio diaphanus Drury,  (Ill. nat. Hist. 2 : index et 13, pl. 7, fig. 3), the type-material of which forms part, therefore, of the syntypes of Hymenitis diaphane Hübner. By the lectotype-selections cited at the head of the present note, the specific name diaphane Hübner became a junior objective synonym of diaphanus Drury.
The name Greta was introduced when it was realized that the name of the genus - Hymenitis Hübner, 1816 - in which the above species had till then been placed was invalid under the Law of Homonymy.
Cowan (1970: 33) stated:-
"DECISIONS PENDING AT I.C.Z.N. (As at 31 December 1969). The status of the following, in addition to the twelve names listed in Annot. Rhop. 1968 (page 8, paragraph 7), are now under consideration by the International Commission;
GRETA Hemming, 1934, Case No. Z.N.(S.) - 1899. The first four depend on action to be taken regarding the earliest, Hymenitis Illiger which, as Hemming shows, is both valid and a senior objective synonym of Mechanitis Fabricius, a name on the Official List. The action taken will affect the junior homonym Hymenitis Hübner, and/or its replacement name Greta."
Greta Hemming, 1964 was requested to be placed on the Official List of Generic Names in Zoology by Cowan, 1970, The Bulletin of Zoological Nomenclature, 26 : 246.
Greta (through Hymenitis Hübner, 1816) was placed on the Official List of Valid Generic Names in Zoology in 1972, The Bulletin of Zoological Nomenclature, 29 (3) : 117.
See also: Hymenitis Hübner, 1816 & Hymenitis [Illiger], 1807.
The higher classification used here follows Lamas (2008).
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Search the Biodiversity Heritage Library (BHL) for references to GRETA and included species.