228 BULLETIN 15 7, U. S. NATIONAL MUSEUM 



Another male taken at the same time has the yellow markings on 

 the hind wings below completely covered by a deep rusty suffusion. 

 This exactly corresponds to the form suffusa of P. m. vvassasoit. 



Occurrence. — Confined to boggy meadows with sphagum adjacent 

 to woods. It is very local, but wherever found it is abundant. I 

 only know it from a single bog crossed by the road between the 

 railroad station at Beltsville and the Department of Agriculture 

 experiment farm. Here it is exceedingly numerous within two small 

 areas scarcely 50 feet square, one on either side of the road; but 

 beyond these limited areas it rapidly becomes scarce in every 

 direction. 



This bog, especially the wetter area where this butterfly is found, 

 is subject to inundation in heavy rainfalls. From the abundant 

 mud left high on the ferns and grass blades after a sudden rise in 

 the water, it is quite evident that the early stages of this insect must 

 be capable of withstanding total submergence of some hours' dura- 

 tion. In the locality where I have found it abundantly at Weston, 

 Mass., the same conditions occur. (See Postscript, p. 256.) 



Habits. — The hovering skipper has a very slow and cautious flight, 

 which, as its wings are moved with great rapidity, gives it the 

 appearance of hovering along as it progresses in a tortuous course, 

 winding in and out among the grass blades 2 or 3 inches below 

 their tips. During flight the body is held at an angle of about 45° 

 with the ground. But in spite of its apparent sluggishness this 

 species seems to spend more time upon the wing than do most skip- 

 pers. When sunning itself on a grass blade the fore wings are 

 held erect and parallel and the hind wings are spread out horizontally. 



Except for the least skipper {Ancyloxypha nv/niitor)^ this is the 

 only one of the local skippers that flies on cloudy days, or late in 

 the afternoon. But it prefers to fly on sunny days, in the shadows 

 of the grass tops. 



Slow and deliberate as is this butterfly under ordinary circum- 

 stances, it is capable of displaying a fair degree of energy if neces- 

 sity demands it. It is very pugnacious and will at once attack any 

 other skipper that comes near it, for this purpose rising up above 

 the grass tops. 



In the bogs with it lives Atrytone fontiac, and hostilities between 

 the two are frequent. Several times I have captured two skippers 

 engaged in combat from 6 inches to a foot or more above the grass 

 tops and found a male of each of these species in the net. These 

 combats, in which the two belligerents circle about each other 

 without changing their position appreciably in relation to the 

 ground, usually end with both dropping into the grass, Poanes 

 massasoit almost directly, the other diagonally. 



