106 THE ENTOMOLOGIST. 



collectors who have a one-sided experience, I inclined to ignore 

 the existence of T. crepuscidaria in its varied forms, but the recent 

 careful discussion of the subject has modified my incredulity. 

 Yet the evidence brought forward by Mr. Tutt, judging from 

 what has been published, appears to me still somewhat incom- 

 plete and unsatisfactory. His resume of the controversy, so far 

 as it has yet been printed, is a destructive criticism of various 

 statements put forward by those who would merge the two 

 species ; but the actual tabulated facts necessary to prove the 

 "separate and distinct life cycles" require to be more precisely 

 set forth to compel conviction ; and when dates are given, the 

 year and locality are not mentioned, — an essential when a range 

 of nearly three months fluctuation is claimed for the date of 

 emergence of both species in differing seasons. It is alleged 

 that a clear four or five weeks elapses "between the first 

 emergence of T. crepuscularia and that of hiiuidiilaria ; and 

 another three or four weeks between the latter and the second 

 brood of T. crepuscularia in any given year." If this has been 

 proved to be the case to the satisfaction of the members of 

 the Entomological Society, before whom the discussion took 

 place, the separation of the two species needs, I think, no 

 further demonstration. But has anyone such a continuous serial 

 collection, labelled with dates, and collected in localities approxi- 

 mate in climatic conditions ? That there is but one species 

 in Ireland all the evidence to hand tends to prove, but it is 

 impossible to predicate a distinct negative so long as the fauna 

 remains so ill explored. I have, however, examples from eleven 

 different places, and have sampled specimens from at least as 

 many more, and one important point which bears on the con- 

 troversy is that in no instance have I met with any Tephrosia 

 in Ireland earlier than the end of the first week in April, though 

 the climate of Derry and Down differs from that of Kerry as 

 much as that of Scotland from Devon ; nor have I any evidence 

 of the occurrence of a second brood. In June, at Killarney, I 

 have found the insect still plentiful, though mostly worn. If, 

 therefore, T. histortata from Perth emerge in March (a particular 

 which I have not yet seen clearly stated), I should consider the 

 case in favour of two species a very strong one. A comparison 

 of fifty-two Irish specimens with some twenty English T. cre- 

 puscularia shows that the former are of a clearer ground colour, 

 less powdered with dark scales; with the elbowed line but faintly 

 shaded externally in most cases. Nevertheless, three or four 

 examples taken with the ordinary form in the same locality 

 cannot, I think, be separated from T. crepuscularia ; and though 

 the average expanse is less, some Irish hiundularia attain an 

 equal size with it. I cannot accept the dictum that the colour 

 and pattern of the two species furnish alone a sufficient basis 

 for separating the species, because both are very variable, and 



