1374 THE BUTTERFLIES OF NEW ENGLAND. 



twisted or broken into joints or links; or there may be very slender stiff bristles, 

 or slenderer hairs, or tliese are flagellate at the extremity with a very fine tliread; 

 cell of same wing usually more than two-thirds as long as the wing; hind wings 

 sometimes tailed or lobed at the extremity of tlie snbmedian nervure, sometimes 

 erose, sometimes also entire. Abdomen generally shorter than the hind wings ; in the 

 male the extremity of the alimentary canal protected beneath by a horny sheath, which 

 extends beyond the centrum, sometimes nearly to the extremity of the parts beyond, 

 thus always carrying the anal opening beyond the centrum ; or, to express it differently, 

 the lateral arms originate from the lower surface of the centrum, from the very base, 

 permitting a passage for the alimentary canal between them and the centrum. 



Egg. Compact, the height about ecjual to the diameter, the sides comparatively 

 higli above, and furnislied with a moderate ntiraber of not very elevated longitudinal 

 ribs, extending from about the edge of tlie base to the flatter portion of summit and 

 crossed liy numerous delicate, transverse lines. 



Caterpillar at birth. Last abdominal segment furnished with simple tapering 

 hairs, witli a slight backward arcuation. 



Mature caterpillar. Comparatively stout, the head more or less quadrangular, 

 al)out as In'iiad al)o\'e as below ; the abdominal segments divided by transverse creases 

 into no more than five sections. 



Chrysalis. Comparatively stout, the Ijoiiy largest at the third abdominal segment, 

 the head genei-aliy a little narrower tlian the thorax; always rounded in front in the 

 middle, but never mucronate; tongue case short, not protruding beyond the tip of the 

 wings. 



The males of the butterflies of this group may, at least in our fauna, 

 be distinguished from those of the other by the presence of a costal fold on 

 the basal half of the fore wings, often obscure, and vvliieh includes a sort of 

 silky down, in general appearance similar to, but more delicate than, that 

 found in the fold of the inner margin on the hind wings of some Papilioni- 

 nae. 



The higher forms comprised in our fir.st section, the Eudamini of 

 Mabille, differ a little from the lower (Antigonini of Mabille) in the mode 

 in which the wings are held in repose, in which respect they generally 

 resemlile, as Wallace has remarked (antea, p. 13(59), the majority of butter- 

 flies, all the wings being equally erect. They also differ from them in the 

 greater stoutness of the body and their remarkable swiftness of flight, 

 "which I believe," says Wallace (Trans, ent. soe. Lond., [2], ii : 3(34), 

 "exceeds that of any other insects. The eye cannot follow them as they 

 dart past, and the air, forcibly divided, gives out a deep sound, louder than 

 that produced by the humming bird itself." These higher genera, too, are 

 almost wholly peculiar to America and entirely absent from Europe, while 

 the lower forms (our second section, the Antigonini of Mabille) are com- 

 mon to both continents, and in the temperate zones are perhaps nearly 

 equally abundant in both. In these lower forms the wings are either per- 

 fectly or almost perfectly expanded, or else they begin to show an inequal- 

 ity of position, mostly peculiar to the tribe below. 



The prevailing color of the butterflies of this group is dark brown, 

 marked with squarish or angular white or translucent spots ; tawny tints 

 are seldom found. The antennae generally have a long club, roundly bent 



