[Taxacom] hönei or hoeni animal species name

[John Grehan]

I would be most grateful for someone with familiarity with the zoological
rules of nomenclature to give me direction with respect to the animal
species name ' hönei' which was rendered in this form in the original
German publication (1949), but I have seen it listed in a later catalog as
'hoenei' which may be a standard rendition when not using the umlaut, but
since the original is written with the umlaut is that the proper or
preferable form for the species name? The document is otherwise in English
text.

Thanks, John Grehna