16 PLATYPTILUS. 



among plants of Arnica angustifolia, at an elevation 

 of about 6700 feet, on Mt. Shasta, California, in 

 August 1871. 



Platyptilus fragilis, sp. nov. 



(PLATE I. FIG. 12.) 



Capite, thorace et alis anticis subochraceo-albidis, ma- 

 cula triangulari, punctis duobus ante medium et 

 linea in basi ciliorum marginis apicalis brunneis. 



Alis posticis dilute brunneis, ciliis pallidioribus. 

 Tibiis posticis albidis, articulis brunneo dilute suffusis. 



Head and thorax yellowish white ; the palpi touched 

 with cinereous. 



Fore wings yellowish white, with the two antemedian 

 spots distinctly indicated ; these and the trian- 

 gular costal patch brown. The apical margin 

 brownish, the brown line running slightly within 

 the cilia scarcely at their extreme base ; two 

 small brownish dots in the cilia of the dorsal 

 margin before the anal angle. 



Hind wings very pale brown, with paler cilia. 



Abdomen and legs yellowish white, the joints only 

 slightly suffused with brownish. 



Expanse 19 millims. 



Two specimens taken (September 7th, 1871) near 



