THE CANADIAN ENTOMOLOGIST. 217 



In May, 1904, my brother, Mr. Harry Cook, called my aiieniion to 

 the fact that some of the males (as proclaimed by the genitalia) were 

 without the stigma. As many specimens were taken as the lateness and 

 unfavourableness of the season permitted, and all the material collected in 

 former years was again carefully sexed. This resulted in a complete 

 readjustment of the previously accepted form-series, and brought order 

 out of chaos (at least among the males). 



Correlated in every instance with the absence of the discal stigma are 

 characters which clearly distinguish these males from typical irus. The 

 most striking are : (i) the uniform blackish-brown of the basal half of the 

 secondaries beneath ; (2) the definiteness of the boundary of this area 

 and its almost equal projection between the median nervules (in irus this 

 projection is constantly greater between the second and third than between 

 the first and second) ; (3) the continuity of the extramesial line running 

 from the costal margin of the primaries — under surface — to the first 

 median nervule (in irus this is represented by a series of short dashes 

 between the nervules, which, being at different distances from the outer 

 margin, give the appearance of a much broken or crenulate line). I 

 moreover failed to find any androconia at all on the individuals without 

 the stigma. There are other differences between the two series quite as 

 noticeable, but not constant enough to serve as distinguishing characters. 



On a basis of the three constant and best differentiated characters of 

 the males, the females were separated very satisfactorily, and in their turn 

 exhibited correlative differences of minor importance. 



The above generalizations are made from sixty-three specimens. 



It is to be noted that the series thus removed from /. irus agrees in 

 detail with the description of /. Ilenrici, as published by Grote and 

 Robinson in 1867 (Trans. Am. Ent. Soc, I., 174). Scudder has sunk 

 Henrici as a synonym ; Dyar retains the name, regarding the forms as 

 distinct. 



The original description fails to mention the stigma, although it seems 

 reasonable to believe that the absence of so obvious a mark would have 

 attracted the attention of two such experienced observers as the authors, 

 especially since its absence from the 9 of another species is remarked in 

 the same paper (p. 173). 



Edwards, who bred what he thought to be a Henrici (Papilio, I., 

 150-152) — the description of the early stages of which has since passed, 

 with many, for a description of the early stages of irus — was certainly 



