424 ON SPECIES OF llADENA SMITH. 



Group devastatrix. 



This group differs from the preceding (spiitatrix), hy the less promi- 

 nent tultings, more eveu outer margin of primaries, the inner angle not 

 retracted, and most obviously by the fact that the terminal space is 

 never darker, but rather paler than thes. t. space, and except in somw^e>•^ 

 the s. t. space is not paler than the median space. The s. t. line in all 

 the species is preceded by a series of sagittate dashes, which are some- 

 times confluent, but always present. The genitalia of two of the species 

 are unknown, but as the others, their near relatives, agree very well 

 in this point with the other typical groups, they will probably not pre- 

 senii anvthiug very peculiar. 



Ducta, of which separans is a synonym, is nearest to the arctica group 

 by the tuftings, which, though perhaps less prominent, are like those of 

 that group. Is a dusky, blackish species and is easily recognized by 

 the small but distinct W mark of the s. t. line. The $ has not been 

 examined. 



Impulsa is a somewhat purplish black species, with deep, velvety black 

 markings and yt How punctiform s. t. line. There is no difficulty in its 

 recognition. The outer margin of tip of $ harpes is somewhat rounded, 

 and as usual, with a fringe of spinules. At the inferior angle there is a 

 brush of longer spines extending half way to the superior angle, which 

 is rather broad, and as usual, excava! ed. The clasper reaches to the end 

 of tip and is slender, somewhat twisted. Inside of this is a shorter, 

 slender, chitinous process somewhat enlarged toward tip. 



Devastatrix, the type of the groui), has the tuftings much reduced in 

 size, and there is a strong suggestion of the Liiperina group in its gen- 

 eral habitus. It varies from pale to blackish gray ; the median lines 

 are rather eveu, geminate, the included space i)ale in dark specimens. 

 S. t. line also rather even, and the sagittate preceding dashes are more 

 or less confluent. The genitalia are essentially like those of impulaa, 

 except that the superior angle is somewhat narrowly prolonged. The 

 clasper is not so long and perceptibly stouter. Altogether, though 

 variable, the species is well marked and easily recognizable. 



Exulis is a northern form and exceedingly variable. It is luteous or 

 rust brown, with blackish or darker powderings, and the veins and or- 

 dinary spots, usually white marked. Often the white powderings ex- 

 tend to other parts of the wing, and often the transverse lines are ac- 

 companied by white shades. From all others in this group it is easily 

 distinguished by the ground color. The tip of 5 harpe differs from the 

 others in the group by having the brush of spines at inferior angle ex- 

 tending along the inferior margin to the superior angle, which is 

 broadly rounded and, as usual, excavated. 



Sommeri is also a northern species, differing from all others in the 

 group by the darker median space, though agreeing in other features. 

 In the two last named species the tuftings are distinct; more so than 

 in devastatrix; less so than in ducta and impulsa. No $ of this has 

 been examined. 



