Hemming (1967) stated:-
[Phocides cruentus Hübner, ] - a nominal species established as a replacement for the nominal species Papilio palemon Cramer, , Uitl. Kapellen 2 (II) : 54, pl. 131, fig. F), the name of which is invalid under the Law of Homonymy.
The first of the three species Hübner recognized as belonging to his genus Phocides was Papilio palemon Cramer, . He realized however that that name was invalid, as being a junior homonym of Papilio palaemon Pallas, 1771 (Reise durch verschied. Russich. Prov. 1 : 471), and he accordingly introduced for Cramer's species the replacement name Phocides cruentus. By an unaccountable misreading of this passage of the Verzeichniss Evans fell into the error of supposing (1952, Cat. amer. Hesp. Brit. Mus. 2 : 7, 8) that the name Phocides cruentus, as there published by Hübner, was a nomen nudum, and accordingly rejected as invalid Scudder's selection of Phocides cruentus as the type-species of this genus. He then declared that the type-species in these circumstances was Hesperia polybius Fabricius, 1793, which was not even mentioned by Hübner. He explained he took this view because "polybius the next oldest name [after palemon Cramer] becomes the type". It is not necessary to pursue these fallacies further, since Evans's arguments all relate to nominal species currently considered either to represent the same taxon or to differing subspecies of the same taxon. In consequence no practical harm results from the mistakes discussed above.
All that is necessary is therefore to note (a) that the name Phocides cruentus Hübner is a nomenclatorially available name, (b) that it is the oldest such name objectively applicable to that species, and (c) that according to subjective taxonomic ideas currently held the taxon represented by the nominal species Phocides cruentus Hübner is a subspecies of the taxon represented by the older-established nominal species Hesperia polybius Fabricius, 1793 (Ent. syst. 3 (1) : 337).
The higher classification used here follows Lamas (2008).
Learn more about Hesperiidae in Wikipedia.
See images at Butterflies of America where it is treated in the subfamily Eudaminae.
Search the Biodiversity Heritage Library (BHL) for references to PHOCIDES and included species.