THE CANADIAN ENTOMOLOGIST. 33 



texture of wing, quite opaque. On the underside, the forewing is not 

 distinguishable in colour or marking from Semidea ; the hind wing is dark 

 — a dusky gray, the band within its bordering lines darker, or brown. It 

 closely resembles Semidea of Labrador, as determined by Moschler. 



I have under view eleven of the Colorado form in question, 5^,6^, 

 and have seen several others. All are or were gray-brown above, of 

 slight texture of wing, so transparent that the white labels on the pins are 

 distinctly seen through the wings when viewed vertically. All have the 

 band beneath the hind wings gray-white within, and there is a consider- 

 able space outside of and next to the band on either side of pure white, 

 forming a conspicuous feature ; the rest of the vving, at base and over 

 extra-discal area, is gray-white. The band has similar outline and 

 breadth to that of Crambis of Labrador, with variations in both species, 

 and the band of the Labrador Semidea is similar to the other two. 



As to the forewing beneath, except that in the Colorado form the 

 colours are paler, that form is closely like Crambis and also Semidea, 

 both of Labrador and White Mountains, of New Hampshire. 



I have eight Taygete Hiibn. from Labrador and Alaska, and the band is 

 of the same character as in all the other species mentioned, varying in 

 outline, but the veins are white in all the eight, as Dr. Staudinger says 

 Taygete should have the veins. Also this species is usually yellow-brown ; 

 one Alaskan example is dark brown. 



In Dr. Staudinger's view the Colorado form is a permanent variety. 

 It certainly is completely isolated, and for untold ages must have been as 

 much so as to-day. A permanent variety in such case is a species. If it 

 originally branched from the Labrador Crambis, and of this we are 

 absolutely ignorant, it has lost all connection ; breeds true, and fulfills 

 every requirement of a species. And as a species I regard it. Consider- 

 ing that we owe all our knowledge of it to Mr. David Bruce, who, during 

 the last three years, has taken great pains to investigate its localities and 

 habits, and has obtained eggs whereby I have been able to rear the 

 species to adult larval stage, I cannot do otherwise than name it 

 Chiofiobas Brucei. 



Mr. Bean, at Laggan, Alberta, has taken a single specimen of this 

 Brucei. Mr. Bruce has taken more than 300, and he tells me the 

 peculiar characteristics which I have enumerated have been found in the 

 whole of them. 



