GENUS THECLA 211 



331. Thecla Mossi. Not figured elsewhere. 



Plate XXVIII; Figure 331, Female, underside, Puget 

 Sound, May i, 1890; Author. 



Mossi is sometimes spoken of as the Western form or repre- 

 sentative of the Eastern species, Irus, which lives in the Atlantic 

 and the Western States. Mossi was taken on Vancouver Island 

 in 1880. and ten years later this figured example was taken by me 

 in the same region. Between this locality and the habitat of Irus 

 in the Western States is a vacant space two thousand miles wide, 

 in which neither Irus nor Mossi are seen, and, considering this 

 fact, and also the differences between the forms, I conclude that 

 Mossi is a good and sufficient species. 



The essential peculiarity of Mossi is the bleached, washed-out 

 appearance of the underside of hind wings, "giving it a most pecu- 

 liar aspect," as the description truly says, and as shown on the 

 plate. 



333. Thecla Eryphon. 



Plate XXVIII ; Figures 333, b, c. 



F'g- 333- Male, Sierra Nevadas near Lake Tahoe, July, 

 1892 ; Auhor. 



b. Female, Sierra Nevadas near Lake Tahoe, July, 



1892; Author. 



c, Female, underside. Sierra Nevadas near Lake Ta- 



hoe, July, 1892; Author. 

 The key to this species is the evenly-curved band near the mid- 

 dle of fore wing, in contradistinction with the next species, Ni- 

 phon, in which the band is sharply angled or dentated ; though 

 the underside of Niphon is much lighter than Eryphon. 



334. Thecla Niphon. 



Pl.\te XXVIII ; Figures 334, b, c. 



Fig. 334, Male, Mendocino County, Cal., June, 1891 ; 

 Author. 



b. Female, Mendocino County, Cal., June. 1891 ; 



Author. 



c. Female, underside, Mendocino County, Cal., 



June, 1891 ; Author. 

 Niphon is much like the preceding Eryphon, being lighter, espe- 

 cially on under side, and the banding beneath is more angulated. 



