138 BULLETIN 15 7, XJ. S. NATIONAL MUSEUM 



blue scaling confined mostly to the base of the fore wings, with 

 scattered blue scales on the basal portion of the hind wings, and there 

 is a distinct, but not brilliant, blue reflection over the entire light 

 area of the fore wings. 



Specimens taken in the vicinity of Boston in July and August 

 most nearly resemble those taken in the District in June. In the 

 males the hind wings are never so brightly marked as in most of 

 those taken in late July. They are also somewhat paler and are 

 often tinged with violet. In the females there is more blue on the 

 fore wings and the blue reflection over the whitish area is stronger. 



Eleven males of the form violacea from the District measure in 

 the length of the fore wings from 12 mm. to 15 mm., averaging 

 14 mm. Five females measure from 13 mm. to 14 mm., averaging 

 13.8 mm. Mr. Scudder gives the average of both sexes as 14 mm. 



Ten males of the form pseudargiolus (or neglecta) from the Dis- 

 trict measure from 13.5 mm. to 16 mm., averaging 14.9 mm. Five 

 females measure from 14 mm. to 15.5 mm., averaging 14.7 mm. 



Four males of the form pseudargiolus from the vicinity of Boston 

 taken in July and August measure from 14.5 mm. to 16.5 mm., 

 averaging 15.5 mm. Twelve females from the same region measure 

 from 12.5 mm. to 15.5 mm., averaging 14.2 mm. 



NOTE 



In addition to the foregoing species of Lycaeninae the following 

 may possibly occur in the District : 



Chrysophanus thoe (see p. 248). 



Olaucopsyohe lygdamus lygdavrms (see 

 p. 248). 



Subfamily Theclinae 



KEY TO THE SPECIES 



o\ Hind wings without tails. 



6\ Hind wings below with a submarginal row of large bright 

 red spots, and also numerous scattered small black spots 

 conspicuously ringed with white (pi. 24, figs. 1, 2). 



Strymon titus (p. 141). 

 &^ No red spots on the under surface of the hind wings, and no 

 scattered black spots ringed with white. 

 c\ Underside of hind wings with the inner half similar to 

 the outer, both crossed by irregular or jagged very 

 dark lines, the central one narrowly bordered with white 

 outwardly, giving an irregularly checkered effect ; bor- 

 der of hind wings conspicuously scalloped (pi. 25, figs. 



9, 10) Incisalia niphon (p. 145), 



&. Underside of hind wings with the inner half darker than 

 the outer, from which it is separated by a very irregu- 

 lar line, and unmarked. 



