35 



ochreous fuscous, with a more or less distinct cluster of dark 

 scales near the middle of the hind fringe of the third feather. 



The genitalia are represented on Plate III., figs. 4 and 5. For 

 the sake of comparison the genitalia of P. ochrodactyla are repre- 

 sented on the same plate, figs. 14 and 15. These were made from 

 specimens received from Professor Zeller, and labelled in his own 

 handwriting. 



The above description was drawn up from one hundred and 

 thirteen American specimens. 



Habitat. Europe; Canada, Maine, New Hampshire, Massa- 

 chusetts, New York, Pennsylvania, Colorado, California, Oregon. 

 Food, Yarrow (Achillea millefolium) . 



In some unpublished notes received from Mr. Charles Fish, I 

 find the following statement : " Received from Mr. J. Elwyn Bates, 

 on June 30, 1881, some eggs of Plat, bischoffii, which were laid 

 June 24, to the number of twenty-four. They were elliptical in 

 outline and somewhat flattened. The longer diameter was three- 

 sevenths of a millimeter and the shorter diameter was three-tenths 

 of a millimeter, and the surface was irregularly corrugated. When 

 first deposited they were of a light cream color or almost hyaline 

 with a glossy surface, but after two days they turned to a deep 

 flesh color." There was no note made as to whether these eggs 

 hatched, or not. 



Different stages of the larva have been described by several 

 writers in Europe, and the mature larva is briefly described as fol- 

 lows : ' ' Larva green ; dorsal line darker or somewhat brownish 

 tinged ; subdorsal and lateral gray whitish ; subspiracular white ; 

 head whitish yellowish." (Meyrick.) 



44 The pupa is a little over half an inch long, with a longish 

 beak in front, projecting at a slight angle downwards from the 

 head ; pointed at the tail ; the wing cases of moderate length, well 

 developed, and the ends of the leg cases projecting free from the 

 abdomen. The color is bright pale green, dorsal line dark green, 

 edged on the thorax with white ; beak white above, rust color on 

 the sides ; there is a conspicuous streak of this rust color on the 

 hind part of the thorax, and the same color also appears (but more 

 faintly) on the abdominal point and at the tip of the leg cases ; 

 subdorsal line dark green, lateral line white. Ventral surface pale 

 green, with darker green lines, and the wing-cases with whitish 

 rays." (Porritt.) 



The insects before me, so far as the labels indicate, were on the 

 wing in Maine, June 24 ; Massachusetts, from the 10th to the 27th 



