THE CANADIAN ENTOMOLOGIST. 311 



The question as to Eudryas is rendered difficult by Hubner's separ- 

 ation of the species by several pages, but virtually it seems to me we have 

 to do with a mixed genus. For the use oi Eudryas for the type unio, we 

 have, then, Boisduval, Harris, Packard, Walker and myself For the use 

 o{ Etdhisanotia ^ox ti/nais, we have the British Museum Catalogue and 

 my own writings. 



Upon a related point, I would say that it is now held generally by 

 European classificators that a change in a new specific or generic title 

 itself or its limitation by an author in the same work or book, or, if a 

 serial, in the same series of papers, or year or volume, must be 

 respected This would cover Guenee's changes of specific names in the 

 Species Gene'ral. We must therefore write Orthodes enervis, Catocala 

 viduata, etc. To this extent at least authors may correct their original 

 publication. There will be no valid objection then to the latter name 

 Orthosia euroa, G. & R. This reading would inferentially show that 

 Hubner's reference of //;«^/.f to Euthisanotia is sufticiently valid for its 

 use as the type of the genus under Boisduval's restrictive action in 1836. 

 We may therefore continue, I think, to use Eudryas for unio and con- 

 generic species. 



The question, I have admitted, is a difficult one, and the view I here 



take of it may be thought not entirely uninfluenced by my respect for the 



nomenclature of Harris's Insects Injurious to Vegetation. It is true I am 



unwilling to lose Eudryas from our lists ; but, if the case was quite clear, 



I should not be free to object. I desire also to show that questions as to 



generic types are not always easy to solve ; tVey demand some thought, 



some study beyond the mere reference to a page in some book. In the 



present case Hubner's prior reference oitimais io Xanthopastis,YerzQ\c\\- 



niss, 1 818, adds to the difficulty. I think it not uninteresting to have 



followed Hubner's action with regard to timais. Evidently the yellow 



dots in" Cramer's figure led him to believe he had to do with a foreign 



species of /'i?//^. Afterwards, when he recognized Cramer's species in 



nature, he was evidently disappointed, and wished to correct the generic 



position of the moth. And, in his new reference, he is equally out of the 



way ; perhaps, indeed, his second mistake is greater than the first. Here 



again it is the gay colours of timais that make him 'associate it with u?iio. 



Both are odd-looking moths, having a differing, while equally strange 



beauty. The notion that in unio and allies we have to do with aberrant 



