Thanks! Are there (or more importantly, were there then) any restrictions on where a validly published description can appear? I know with botanical publication newspapers are not admissible as formal publications, presumably because they are not considered permanent enough. What the Literary Gazette would count as, I don't know.This issue of the Literary Gazette bears the date "Saturday, March 27, 1852".
I don't known if the dates of the Zoologist are precisely known, but a note dated "Charlton, Dundrum, near Dublin, April 14, 1852", appears two pages ahead of the description. (The name must have been published there after this date, plus the time needed for a letter to reach London from Ireland, plus the time needed to have it printed in the journal.)
The two texts seem identical.