76 THE COMMONER BUTTERFLIES. 



7. Genus Akgynnis. 

 ARGYNNIS ATLANTIS— THE MOUNTAIN SILVER SPOT. 



Butterfly. — Upper surface of wings orange fulvous, witli well- 

 defined black markings. These consist, in all our species of 

 Argynnis, in the fore wings, of three sinuate bars across the 

 outer part of the cell besides a straight and a sinuate bar at the 

 tip, a more or less disconnected zigzag band across the middle of 

 the wing, and a series of rounded spots on the middle of its outer 

 half, besides a submarginal series of sagittate spots on a dusky 

 border. On the under surface the design of the fore wingt: is a 

 vague repetition of the upper markings, while the hind wings 

 have submarginal, extramesial, intramesial, and prebasal serit-s 

 of very large silvery spots, those of the outer series usually the 

 larger. The peculiarities of each species are seen principally on 

 the under surface of the hind wings, which in the present species 

 is distinguished by the depth and griminess of the basal tint and 

 by the width of the buff belt between the two outer rows of silver 

 spots, which is intermediate in this particular between A. aphro- 

 dite and A. eijhele. Expanse 2^ inches. 



Caterpillar. — Head dark. Body spinous, dark velvety purple 

 above, scarcely paler beneath ; spines corneous, livid at base, the 

 spinules nearly half as long as the spines. Length 1^ inches. 



Chrysalis. — Chestnut-brown irrorate with black, basal seg- 

 ments of abdomen unicolorous; dorsal and ventral surfaces of 

 front part of body set at an angle of about 50^ Length | inch. 



The eggs, which are short sugar-loaf-shaped, as high as 

 broad, with twelve to fourteen vertical ribs and honey-yel- 

 low, are laid singly on the food-plant and hatch in about 

 a fortnight. The caterpillars go into winter quaiters im- 

 mediately after emerging from the Qgg without tasting of 

 vegetable food, a^vake early in the spring, and feed singly 

 and by night upon violets, hiding in crevices by day. The 

 chrysalids are found attached to the under side of logs 

 lying on the ground and in similar places; their period is 

 unknown. The butterfly is wilder than the succeeding 

 species of the genus and is a more northern form, being 

 limited southwardly by about the annual isotherm of 45° F. 



