66 BULLETIN 15 7, U. S. NATIONAL MUSEUM 



This butterfly is confined to wet meadows bordered or surrounded 

 by woods and closely adjacent to, or traversed by, a running stream, 

 especially on hillsides or at the base of rising ground. It also oc- 

 curs, sometimes plentifully, in deep valleys or ravines where the 

 banks of the stream become boggy and grassy, forming a wet open 

 glade. From time to time it is found in unusual abundance. 



Habits. — The grass nymph is so very local that unless one happens 

 to hit upon just the right locality it is likely to be overlooked. 



This butterfly has a very irregular, languid, dancing flight, rising 

 but a foot or two above the grass tops. It especially loves to flit 

 through buttonbush and clumps of alder growing in the bogs, and 

 it is most active just within the borders of the woods adjacent to 

 the bogs in which it lives, where, however, only the males are to 

 be found. Here it flies more strongly and higher than in the 

 open, and is much more wary and alert. Here only it seems to 

 play. In the mottled shade two belligerent males will sometimes 

 rise fluttering to a height of 10 feet or more, though in the grassy 

 areas the butterflies seem to pay little or no attention to one another, 

 no matter how numerous they may be. 



When frightened the grass nymph either rushes off with a very 

 rapid, direct, and rising flight, which is its usual habit in the woods, 

 or darts to cover in the interior of a bush, or after a short dash 

 drops into the grass and there conceals itself. 



In general, the actions of this butterfly are much like those of the 

 wood nymph. It has the same quick, nervous motions, and when 

 sunning itself usually sits side to the sun with its wings tilted at 

 right angles to the rays, but occasionally back to the sun with the 

 wings partially expanded. 



Season. — This butterfly first appears in the first week in June, 

 becomes common by the middle of the month, and is found in great- 

 est abundance in the middle of July. Toward the end of July the 

 numbers decrease, but it remains on the wing until nearly the middle 

 of August. Mr. Shoemaker writes me that he has found it quite 

 common along the Eastern Branch about the middle of June, and 

 one of the two specimens from the District in the Schonborn col- 

 lection is dated June 15. I found it very common on July 15 and 

 23 in the bog at Beltsville, where there were still a few much-worn 

 individuals on August 5. Mr. Shoemaker has a specimen which he 

 caught on the Eastern Branch on September 23, 1927. 



About Boston this insect, according to Mr. Scudder, usually ap- 

 pears about July 7, occasionally as early as the 1st or as late as the 

 15th. Generally it is abundant by the middle of July. Toward the 

 end of the month it is much less common, and also badly torn and 

 rubbed, but it continues until after the middle of August. 



