Hemming (1967) stated:-
Following the rejection by the Commission (in its Opinion 97) of the leaflet entitled the Tentamen of 1806 and therefore of Oreas and the other names first introduced in it, it is necessary to ascertain by whom, when and where the name Oreas was first subsequently used as a generic name in conditions which satisfy the conditions of the Code. This is found to be Hübner himself in volume 1 of his Sammlung exotischer Schmetterlinge, where he applied this name to the species figured on fifteen plates (pls -). These plates were published on various dates between 1807 and 1819, and, as shown by the survey of the surviving Hübner manuscripts (Hemming, 1937, Hübner 1 : 403) the first was published as early as 1807. This is plate , which depicts Papilio piera Linnaeus, which is therefore the type-species by monotypy.
The name Oreas Hübner, , as defined by the foregoing type-species, is an objective synonym of the well-known name Haetera Fabricius, 1807. As these names were published in the same year and nothing definite is known as to the precise date in that year on which the name Haetera was published, while it is known that the name Oyeas Hübner was published at latest by 22nd December of that year, the name Oreas Hübner would, other things being equal, take precedence over the name Haetera Fabricius. This is only one of a number of cases in which Hübnerian names in volume 1 of the Sammlung are either slightly older than, or of the same date as, well known Fabrician names of 1807. Great confusion would have resulted if these virtually unknown Hübnerian names had in any of these cases been substituted for their long-established Fabrician counterparts. To obviate this risk an application was submitted to the Commission in 1935, asking for the protection of Fabrician names threatened in this way, three Fabrician names (Morpho ; Helicopis ; Pontia) with their Hübnerian counterparts (Potamis ; Rusticus ; Mancipium) being cited as examples. The request so submitted was approved by the Commission, whose decision was promulgated in Opinion 137 published in 1942 (Opin. int. Comm. zool. Nom. 2 : 21-28), the Commission ruling that generic names published on the legends of plates in volume 1 of Hübner's Samml. exot. Schmett. in 1807 were to take precedence after any corresponding names published by Fabricius in the same year in volume 6 of Illiger's Magazin.
Under the Commission's Ruling cited above, the name Oreas Hübner, , takes precedence after the name Haetera Fabricius, 1807. Accordingly, as these names are objective synonyms of one another, the name Oreas Hübner, , is invalid, as being a junior objective synonym of Haetera Fabricius, 1807.
Cowan (1968: 7) stated:-
Opinion 789 ruled 65 generic names to be invalid, the following three being of butterfly genera;
Hamadryas Boisduval, 1832; Nereis Hübner, 1806; Areas Hübner, 1807.
It should also be noted that Oreas Hübner, though invalidated as a junior synonym of Haetera Fabricius, is not suppressed for the Law of Homonymy, and remains available to prevent use of its own junior homonyms. So Oreas C. & R. Felder, 1865 remains invalid and Rusalkia Kirby, 1871 (List [Hemming, 1967] : 397) still stands.
The higher classification used here follows Lamas (2008).
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