304 THE BUTTERFLIES OF NEW ENGLAND. 



delio-hts to rest and bask in the noonday sun " ; Gosse mentions seeing 

 ' ' as many as sixteen of this species crowded together on an old log by 

 the roadside, so close together as to be almost touching in every part." 

 ]Mr. Emery found them associating with the marsh-loving Euphydryas, prob- 

 ably the result of their partiality for moisture ; they may always be found 

 in companies on the moist ground about the water troughs placed by the 

 roadside in the hilly country, and they start almost from beneath one's 

 feet in the gloomiest part of the damp forest road, where, if one but wait 

 patiently, the startled beauties will reassemble and the choicest may be 

 readily captured. 



" When alarmed," says Edwards, "it darts swiftly away and courses 

 up and down the path, or flies into the trees, but will soon return. . . . 

 It flies at some distance from the forest also, and visits orchards for the 

 rotten apples, and farm houses for the chance of what it may find to its 

 likino-." It is very fond of all excrement or other moisture. Edwards 

 tells us how its body becomes distended when fed in a vivarium on 

 sweetened fluids, and Jack relates how it will feed on the sweets exuded 

 from the caruncles of plant lice. D'Urban found it " very restless and 

 active when on the ground, constantly opening and shutting its wings, 

 unrolling its tongue, and running to and fro very rapidly, and even when 

 feeding is not easily surprised. It flies freely in cloudy weather and quite 

 late in the afternoon." Although, as Jones says, it sometimes mounts to 

 the tops of the highest trees, it usually flies only two or three feet above 

 the ground, along the road, sailing on its broad wings rather than flying, 

 or if not sailing, moving slowly with a rapid but very short flutter. It is 

 very social in its nature, as the statements given above of its abundance 

 show. Alighted together they are nearly always still very active, chang- 

 ing their position constantly and crowding against one another, so that 

 their wings are soon abraded. 



When fairly at rest in such a position, the wings are closed back to 

 back, the fore wings so far advanced as to leave two of the smaller sub- 

 apical white spots visible beyond the margin of the hind wing ; the body 

 is raised at an angle of 45'^ with the ground ; the antennae are straight 

 except for a basal arch when seen from the side, parallel to the body, and 

 divaricate at an angle of 1)0°. 



Dimorphism. This s])eeies is looked upon by Edwards as dimorphic, 

 the alternative form being known as proserpina. My reasons for thinking 

 otherwise have been given separately under the head of the latter form, 

 where I regard it as a hybrid between 13. Ursula and B. arthemis. 



Mimicry. The only evidence of mimicry in this species is in the early 

 stages. In connnon with the other species, both larva and pupa resemble 

 the dro[)ping of birds. I have already related that an unknown noto- 

 dontian feeds upon black birch in the same manner and stations as 



