ART. 11 COMMOX OLD WORLD SWALLOWTAIL BUTTERFLY — CLARK 15 



able, this form apjjears to be well defined and stable throughout the 

 greater i^art of its range ; but in central Alaska it becomes very vari- 

 able, and with it is found a third form, P. m. j)etersii^ which ap- 

 proaches the Kamchatkan P. m. kamtschadahis, being intermediate 

 between P. m. hudsonianus and P. m. kamtschadalus. Although P. 

 711. petersii is very different from typical P. in. alio^ka^ the two seem 

 to intergrade in the region in whicli both occur. 



KEY TO THE AMERICAN SUBSPECIES OF PAPLLIO MACHAON 



a'. Dark border of hind wings broad, the distance from the inner 

 loargin of the border to the black bar at the end of the cell 

 less than the length of the bar; dark border of hind wings 

 beneath narrower than above, the black lines in the inter- 

 spaces delimiting the dark border interiorly widely discon- 

 tinuous except for the two uppermost; tails of hind wings 

 moderate in length or rather long, the distance from the 

 tip of the tail to the deepest portion of the scallop just above 

 its base being greater than the distance between the tips 

 of the veins on either side of the tail ; outer border of fore 

 wings approximately straight ; dark markings above black ; 

 Plate 2 (Alaska and adjacent portions of Yukon and 



Mackenzie) aliaska. 



a-. Dark border of hind wings narrower, the distance from the 

 inner margin of the border to the black bar at the end of the 

 cell greater than the length of the bar ; dark border of hind 

 wings beneath not narrower than above, the black lines in 

 the interspaces delimiting the dark border interiorly almost 

 continuous; tails of hind wings short, their length from the 

 tip to the deepest portion of the scallop just above their base 

 being considerably less than the distance between the tips of 

 the veins on either side of the tail; outer border of fore 

 wings distinctly convex; dark markings above brown. 

 V. Larger, the fore wing about 40 mm long; submarginal spots 

 on lower surface of fore wing rounded and entirely dis- 

 tinct from each other ; submarginal lunules on under side 

 of hind wings of moderate size, the inner edge of the 

 second and third from the costal border lying much less 

 than halfway from the outer edge of the interspace to the 

 inner margin of the dark border; posterior portion of the 

 black margin of the orange anal ocellus expanded into a 

 broad oval patch deeply encroaching on the ocellus ; Plate 



3 (Hudson Bay to Lake Superior) hudsonianus. 



1-. Smaller, the fore wing about 37 mm long; fore wings below 

 with a broad light submarginal band crossed by dark hair 

 lines at the veins; submarginal lunules on lower side of 

 hind wings large, the inner edge of the second and third 

 from the costal border lying halfway between the outer 

 edge of the interspace and the inner margin of the dark 

 border; lateral and posterior narrow black edging of 

 the orange anal ocellus of uniform width, the ocellus being 

 circular; Plate 4 (central Alaska) petersii. 



U. $. EOVERNUENT PRINTINC OFFICE: 1932 



