BUTTERFLIES OF THE DISTRICT OF COLUMBIA 211 



THANAOS BRIZO BRIZO (Boisduval and Le Conte) 



Plate 52, Figures 1, 2 



Occmm'ence. — Mr. Shoemaker has taken this species in the District 

 early in spring, and there are four specimens from the District in 

 the Schonborn collection. 



I have seen it in the woods between Cabin John and Great Falls, 

 and it is especially nmnerous in the woods along Paint Branch. 



Remarks. — This species frequents woodland roads, and open and 

 especially rocky places in woods. While the females remain always 

 in the shelter of the woods, the males wander out over open fields, 

 where they are found with the much commoner T. jtovenalis. 



It flies in April and May, disappearing shortly after the middle 

 of the latter month. It appears again in much smaller numbers in 

 August, being here partially double brooded. 



Mr. Scudder describes it as flying swiftly with frequent sudden 

 movements from one side to the other, but always remaining about 

 3 feet above the ground. Here it flies rather lower, being seldom 

 seen as much as 2 feet above the ground. It is very alert and quick, 

 and Mr. Scudder says that it is the most difficult of all our species 

 to capture. I have found this to be true in New England, but the 

 relatively small individuals occurring here are less energetic than 

 T. juve?ialis, and do not fly so high. 



The caterpillar feeds chiefly on scrub oak, though also on other 

 plants. 



THANAOS PERSIUS (Scudder) 

 Plate 52, Figures 8, 9 



Occurrence. — I have specimens from the fields beyond Cabin John 

 taken on April 14, 1929, June 3, 1923, and July 29, 1928. Mr. Shoe- 

 maker has one from Arlington County, Va., taken on July 9, 1908, 

 and there are three specimens from the District in the Schonborn 

 collection. 



Remarks. — Though found along woodland roads and about rocks 

 in woods, this species is more common in open fields than most of 

 its relatives. Mr. Scudder says that this butterfly is fond of alight- 

 ing on wet sand and may most frequently be found by shady road- 

 sides near woods, seeming to frequent the vicinity of hazel. He 

 describes it as flying with a strong rapid movement, especially when 

 disturbed, and seldom passing from one spot to an adjacent one with- 

 out describing several irregular and rapid circles, and says that at 

 such a time it rarely rises more than 2 or 3 inches above the ground. 

 He noticed that it is an uneasy insect, difficult to suit; no sooner 

 does it alight on a choice bit of moist shady ground than off it starts 

 again, and in alarm it shows the greatest uneasiness. According to 



