PIERINAE: THE GENUS XANTHIDIA. 1063 



ment beneath with exceedingly large and lu'oail nianimillatc protuberances deeply sul- 

 cated longitudinally in the middle. 



Chrysalis. Of the general form of Callidryas but with less protuberant wing cases, 

 straighter form and shorter frontal prominence ; the general outline of the dorsum 

 is nearly straight, the head and frontal prominence being in nearly the same line with 

 the abdomen, but the abdomen has a very broad arcuate sweep, while the line of the 

 head and frontal prominence is almost straight. The thoracic curve is al.so gentle as 

 in Callidryas; the projection beneath, formed by the wing cases, is very great, their 

 outline being strongly arcuate, at their extreme forming an arc of a circle whose 

 opposite arc would scarcely reach the dorsum of the tirst abdominal segment. Seen 

 from above the form of the chrysalis is very slender, slightly broadest at the middle 

 of the thorax, in front of whicli the head and frontal projection have an almost uniform 

 conical shape, reaching almost to a point ; at the hinder edge of the wings, the body is 

 swollen, but almost imperceptibly, and beyond it the abdomen tapers with great 

 regularity to the truncate cremaster; frontal projection regular, conical; prothoracic 

 stigmata with no visible opening; tongue small, surpassing the tips of the antennae 

 and reaching almost or quite to the height of the strongest curve of the wing cases. 

 A well-marked carina runs backward close to the inner margin of the upper wing, 

 becoming obscure the moment it passes its limits and beyond that becoming a small, 

 scarcely perceptible, stigmata! ridge to the lower lateral angle of the cremaster, just 

 before reaching which it again becomes distinct; so, in front of the basal wing tuber- 

 cle, there is a slight indication of its presence in a low, broad, scarcely perceptible 

 ridge, running to the base of the frontal projection. The thoracic dorsal elevation 

 is also slightly compressed and follows as a blunt, low ridge to the cremaster, forming 

 along the crest a fine mediodorsal sulcation on the thorax. Surface obscurely vermicu- 

 late. Cremaster tetraqnetral, broader below than above, all the sides broadly sulcate, 

 but especially beneath, where it is also pi-ovided apically with a deep medioventral 

 sulcation, of which there are faint Indications also upon the segments in advance of it 

 and especially upon the eighth. The truncate extremity of the cremaster is strongly 

 transverse. Hooklets not very large, with a slender stalk which tapers from apex to 

 base, and is crowned with a very large, almost hemispherical, reversed cup, three or four 

 times as broad as the base of tlie stalk. 



This American genus is composed of a single species, which extends 

 east of the Rocky Mountains from the middle of the Alleghanian fauna to 

 Guatemala and perhaps to Brazil, including at least some of the larger 

 Antilles. 



The buttei-flies are medium sized Pierinae and may be distinguished 

 from others with rounded wings, by the form of tlie dark border of the 

 fore wings, which is confined to the upper surface and conspicuously con- 

 trasted with the deep orange disk ; this border starts a little beyond the 

 middle of the costal edge and runs toward the middle of the oiiter margin, 

 then turns, forming a broad outer border, extending, in the male, to the 

 inner margin ; there is a similar broad border on the hind wintrs of the 

 male, but in the female this only appears on the upper half. The under 

 surface is much paler, especially that of the hind wings, which is flecked as 

 in Eurema. 



The single species is probably double brooded, wintering in the imago 

 state and appearing fresh in May and August. 



Dr. Gundlach states that the flight of the butterflies is rapid, continuous 

 and unvaried. They frequently alight on flowers and, like many Ehodo- 



