40 PROCEEDINGS OF THE NATIONAL MUSEUM. 



almost as large as americana, but is of a bluish ash gray, very densely 

 powdered with black scales. The secondaries in the male are white, 

 with a faint, smoky gray tinge, and in tlie female they are gray pow- 

 dered. As a whole, the female is darker and larger than the male, 

 but the difilerence is not nearly so striking as in hastulifera. The 

 psi mark, opposite the anal angle of primaries, is barely indicated by 

 a diffuse shading which does not cross the transverse posterior line. 



Dacfylina is of a bright bluish gray, powdered with black atoms, but 

 not so densely as in the preceding, than which it seems, therefore, 

 decidedly paler. The secondaries are white in the male and grayish, 

 powdery In the female. The ^jsi mark, opposite the anal angle of the 

 primaries, is distinct and crosses the transverse posterior line. 



Of the species in this series it may be said, in recapitulation, that 

 americana is distinguished by its large size and very dusky seconda- 

 ries. HcsperuJa is almost as large, but is bine gray, the secondaries are 

 nearly white in the male, and there is no jjsi mark crossing the trans- 

 verse posterior line opposite the anal angle of primaries. Hastulifera 

 and dactyUna both have the psi mark, but the former has a distinct 

 yellowish shade in both sexes, and smoky secondaries in the female, 

 while the latter is bluish gray and powdery, and the secondaries of the 

 female are gray. As between the males of these latter species there 

 can rarely be <loubt. As between the females some forms of dacfylina 

 can be separated from hastulifera only by the secondaries. 



In the series in which there is a black basal dash, streak, or line 

 three subdivisions are recognizable: First, where the basal streak is 

 linear, terminating acutely and extending to the point which would be 

 occupied by the transverse anterior line were it present; second, where 

 the basal streak is very short and does not reach the point where the 

 transverse anterior line is or might be marked — in this case it is quite 

 usual to have the transverse anterior line marked in the submedian 

 interspace by an angular mark; third, where the basal dash or streak 

 reaches to and joins the transverse anterior line or the angular mark 

 which invariably indicates it. This basis for subdivision seems at tirst 

 sight to be rather slight, but a large series of specimens of each species 

 proves that it holds good. There are cases, of course, where a speci- 

 men may at first seem doubtful, but such are usually due to an imper- 

 fection in the example or to an aberration which is rarely the same on 

 both wings. 



In the first subdivision, where the streak is slender and the trans- 

 verse anterior line is wanting, there is a tendency to a strigate type of 

 maculation. In felina, which is a very dark blue-gray, all the trans- 

 verse maculation is lost, save that the transverse posterior line may be 

 present as a paler shade. The other lines are rarely even indicated on 

 the costa and the ordinary spots are practically wanting. There is no 

 dagger mark opposite the cell. 



Frigida is a close ally of and has been mistaken for felina. It is 

 somewhat broader winged, however, has the transverse posterior line 



