PIERIS. 



317 



examples from as widely distant places as Massachusetts and the 

 Great Slave Lake, though the suite of specimens with which I 

 have made my comparisons would seem to indicate that the paler 

 forms are more commonly met with in the more southern localities, 

 and the more heavily marked ones are the characteristic forms of 

 the north. It may be noticed in this connection that Kirby, by a 

 comparison between a single specimen from Massachusetts with 

 three from lat. 65 K, separated the northern from the southern 



as being less heavily marked. 



SCCDDEK. 



P. protodice BoiscL (p. 17). Scudder, Pr. Boston N. H. Soc. VIII, 

 1861, 180. 



An examination of a large number of specimens in the collection 

 of the late Dr. Harris, in that of the Museum of Comparative 

 Zoology, and in my own, has shown me that this butterfly also 

 enjoys a wide geographical range, extending from Texas on the 

 southwest, Missouri on the west, and the mouth of the Red River 

 of the North on the northwest, as far as Connecticut, and the 

 southern Atlantic States on the east. 



Coincident with these widely separated geographical limits is its 

 wide range of variation, especially to be noticed on the under sur- 

 face of the secondaries, wherein it corresponds remarkably with 

 P. ohracea. On the one hand, we have secondaries which are 

 immaculate, save some scarcely perceptible yellow scales on the 

 discal nervule, bordered by a very few scattered gray scales, a 

 cluster of a few distant gray scales near the border, between the 

 first and second superior nervules, and a dozen or so, more widely 

 separated, similarly situated between the second and third, and the 

 edge of the wing light greenish-gray, with the fringe white. On 

 the other hand, we find greenish-gray scales spread quite heavily 

 along the borders of all the nervures, with the exception of the 

 basal half of the superior and first inferior nervules, which being 

 clustered together toward the border into arrow-head spots, and 

 uniting together at their widest portion, form a transverse zigzag 

 bar ; in the place of the few grayish scales, between the first and 

 second superior nervules, we have a large spot of greenish-gray 

 extending across the first superior nervule to the border; a few 

 scales only border the anterior half of the third superior and first 

 inferior nervules, and the yellow scales of the discal nervule are 



