NYMPIIALINAE : THE GENERA OF AllGYNNIDI. 505 



the i)iili- u[)on the l)a('k of the first thoracic segment is very often larger 

 than the others. They feed principally upon violets. The chrysalids are 

 moderately angulated, holding, as it were, a position midway between the 

 preceding and the succeeding tribes. The species are sometimes single 

 brooded, sometimes double brooded or more, and the history of the broods 

 is often more complicated, apparently, than in any other tribe of butter- 

 flies, largely due, as it would seem, to the periodic or occasional dormancy 

 of the caterpillar. They generally winter as juvenile, sometimes as half 

 grown caterpillars, rarely or never as eggs, chrysalids, or full grown cater- 

 pillars, but perhaps in some instances as butterflies. 



Table of genera of Argynnidi, based on the egg. 



A^ertical ril)S very numerous, more than thirty in number Euptoieta. 



Vertical riljs less numerous, not more than twenty-five in num)>er. 



Vertical ribs j^enerally less than eighteen; egg at most scarcely taller than broad. 



Egg broader than tall, tapering rapidly Speyeria. 



Egg taller than broad, tapering moderately Argynnis. 



Vertical ribs generally more than eighteen; egg considerably taller than broad. Brenthis. 



Table of genera, based on the caterpillar at birth. 



Only two longitudinal series of appendages on either side above the spiracles Euptoieta. 



More than two longitudinal series of appendages on either side, al)ove spiracles. 



Hairs scarcely slenderer before enlarged tip than at base ; two hairs arising from each of 



the subdorsal warts Speyeria, Argynnis. 



Hairs distinctly though slightly tapering to enlarged tip ; one hair arising from each of the 

 subdorsal warts Brenthis . 



Table of genera, based on the mature caterpillar. 



Spines fully as long as the segments of the body. 



Upper spines of first thoracic segment longer than the rest and distinctly enlarged at tip, 



the others equal Euptoieta. 



Most of the upper spines of abdominal segments a little longer than the rest, the others 



subequal , Speyeria. 



All the spines of upper row equal or subequal, and similar to the rest Argynnis. 



Spines only about half as long as segments of body Brenthis. 



Table of genera, based on the chrysalis. 



Upper rows of tubercles on the abdominal segments equal. 



Front of head regularly arched between the ocellar ribbons Euptoieta. 



Front of head laterally tuberculate between the ocellar ribbons Speyeria, Argynnis. 



Upper row of tubercles on abdominal segments unequal, those of third segment l>eing largest 

 and those of fourth segment minute Brenthis. 



Table of genera, based on the imago. 



Second superior subcostal nervule of fore wings arising beyond the end of the cell. 



Fore wings nuich produced at tip, costa well arched at base, outer margin except the apex 



concave Euptoieta. 



Fore wings not produced at tip, costa scarcely arched at base, outer margin convex 



throughout Brenthis. 



Second superior subcostal nervule of fore wings arising before the end of the cell. 



Middle joint of palpi only about one-fourth longer than the longest diameter of the eye.... 



Speyeria. 

 Middle joint of palpi more than three-fourths longer than the longest diameter of the eye.. 



Argynnis. 



6+ 



