The supposed “types” of Guenée in the British Museum have been examined, with the result that some well-established names of Noctuids have been displaced by an uncertain determination. Guenée's collection, which I saw in cbateaudun during the lifetime of the author, is now with M. Oberthier, and should be looked through. But the only evidence we have which is vital is the original description; where this is inapplicable the name should not be used. Only on this evidence can we assume that any of the British Musenm specimens are the real types of either Walker or Guenée, because the collections have not been kept intact as Walker left them, and because no type labels were attached by the latter to the specimens. In these pages I have, I hope successfully, rehabilitated Mamestra lubens, and, by publishing the following translations, perhaps other undoubted names may be restored to their rights. I maintain, for instance, that whatever may be written on the subject, a name like Apatela subochrea should always be retained for the species, in reference to the contradictory opinions which have appeared in print. What we want is certainty in designating the object, and, when circumstances clearly admit of doubt and authors disagree, the sure title should be preferred in every case. There is now far more confusion as to specific titles of our Noctuids than formerly, when the current determinations were mainly supplied by me.