PROCEEDINGS. 1910 7 



ON THE SPECIES OF THE GENUS PERO OCCURRING IN 

 BRITISH COLUMBIA 



By \i. II. P.Iackmore, \'icturia. B.C. 



For many years the species of the genus Pero were a puzzling- one 

 to geometric! students, and it was not until the year 1910 that the late 

 John A. Grossbeck, of New Brunswick, N.J., revised this group and 

 placed the different species upon a satisfactory basis. 



Pero, the name by wliich this genus is now known, was applied by 

 Herrich Schaeffer in the year 1850. and it supersedes the old name of 

 Azelina Guenee by which it was known for so many years, and it also 

 includes the genus Marmarea which was erected by Hulst in 1896. 

 This latter was made a distinct genus owing to the fact that the male of 

 occidentalis had dentate antennae. 



In the species separated by Grossbeck in his revision two have 

 dentate antennae in the males, all the others having filiform antennae. 

 In regard to this difference in antenna! structure, Grossbeck in his 

 Monograph (Proceedings of the U.S. National Museum, \'ol. 38, 19!0) 

 says : "occidentalis has dentate antennae in common with Colorado, but 

 this in my opinion can hardly be considered of generic value, especially 

 in view of the fact that occidentalis in habitus and genitalic structure has 

 strong affinities with modestus a species with filiform antennae, while 

 Colorado has affinities in the same peculiarities with morrisonatus, also 

 a form with filiform antennae. For these reasons I have regarded the 

 genus as identical with Pero." 



This means that the two species with dentate antennae differ more 

 from each other than they do from those with simple antennae. The 

 markings of this group, although similar in outline but differing in 

 colour, are very well defined and quite distinctive. The ground colour 

 varies from light gray and light ochreous through all their var}-ing 

 shades to dark umber-brown. The fore wings are divided into three 

 transverse regions, the basa! and outer thirds generally being of the 

 same shades of colouring, while the median band is very much darker, 

 becoming more intense as it approaches the extra-discal line. In some 

 species the intra-discal line is partially obsolete, giving them the appear- 

 ance of a single division. The hind wings are divided by a slightly 

 curved or undulate line, which crosses the wing outward of the middle, 

 terminating at the inner margin. Now, this concludes my generic refer- 

 ences, but before speaking of the species with which we are most inter- 

 ested, I would like to say that prior to the time when Mr. Grossbeck 

 undertook his investigations, only two species were recognized, viz. : 

 Honestarius Walker (the ancetaria of our lists) and occidentalis Hulst. 

 Mr. Grossbeck had for a long time thought that there were many forms 

 going under the name of honestarius, and he set to work to gather as 



