THE CANADIAN ENTOMOLOGIST. 315 



Hydrcecia in 1S99, by Prof. J. B. Smith. At that time material was com- 

 ]:iaratively scarce and llie hirval histories mostly unknown, but it has been 

 a matter of satisfaction that subsequent breeding and larval studies have 

 been confirmatory of the new features there advanced. There was, 

 however, one question, one oversight apparently that never could be 

 fathomed. 



Illustrations in the Revision were of male structures only, and one, 

 fig. 25, on plate II, presumed to represent cerussata, v.-as found to be in 

 error. Cerussata had later become j^lentifal through the discovery of its 

 larvie, and the genitalia were duly examined to note the "break" occurring 

 with ir, as chronicled in that publication. But it was found to be entirely 

 typical, wtll represented by such a large structure as is shown at fig. 23. 

 Prof. Smith went over it again, and agrees that there has been some over- 

 sight, that he must have figured some other which he mistook for the 

 Grote species. 



But what ? This was a frequently-recurring question, and its 

 elucidation seemed temote indeed. So the suggestion that thdlictri \\-\2iy 

 be this mistaken species finds confirmation in an examination of these 

 structures, and it seems that fig. 25 is no error in itself, only it is wrongly 

 labelled. 



Th''s conclusion naturally leads to another view-point, from which we 

 now see thalictri in a new light. Aniong the larv;e of this si)ecies a few 

 have produced, in rearing, a form in which the stigmata are concolorous 

 with its general tone, and which has been characterized under the varietal 

 name pero^soleia. This feature of instability in the coloration of the 

 stigmata is common to a number of species, and when series are not 

 sufficiently complete to show gradations, there is quite a superficial 

 difference in the appearance of the extremes by reason of contrast. Now 

 fig. 25 of the phte in que-.tion (thalictri) is almost identical with fig. 26, 

 representative of f/igida. And what do we find to separate the latter 

 from the fijrm with concolorous stigmata? Nothing in the description 

 and nothing in the tyi^es, except the usual difference between flown and 

 bred material. It would then appear that thalictri, Lyman, 1905, will fall 

 \.ofr?gida, Smith, 1899, at which earlier date the form having concolorous 

 stigmata was described. There naturally arises the question at the 

 meeting of species showing two superficial forms in the colour scheme, 

 which is typ'cal and which is varietal, especially in a case where it is 

 deemed wise to name both. The prevalence of one against the fewness 



