June, 1896.] 
Dyar: On the Origin of Pericopidae. 
69 
As to the origin of this family, three alternatives seem possible : 
(1) from the Arctiidae (2) from the Noctuidae (3) from the Dioptidae. 
(1) . This alternative seemed to me at first sight most plausible. 
However, the subcostal vein of secondaries in the Pericopidae is free 
from the radius and the wart formation of the larva is of a simple type. 
Therefore, if of Arctiid origin, they are a branch representing a more 
generalized type than the present Arctiidae. But no confirmatory evi¬ 
dence for this possible origin occurs to me. 
(2) . By pushing the origin a little further back, we reach a deriva¬ 
tion from the Noctuidae. This involves an independent wart formation 
from that in the Arctiidae; that is that we may suppose that the Arcti¬ 
idae and Pericopidae arose simultaneously, or nearly so, from Nociuid 
ancestors, but independently and with separate larval wart formation, 
the Pericopidae remaining the more generalized. I do not think of 
any confirmatory evidence for this view. 
(3) . The Pericopidae and Dioptidae differ in that in the former 
cubitus is four-branched while three-branched in the latter. This dis¬ 
tinction is not sharp, since in Gonorct heliconiata ( a Pericopid ) vein 5 
arises only a short distance below the fold representing media. In Di- 
vptis pheloides , Phryganidia californica and Tithraustes haemon (Diop¬ 
tidae ), vein 5 is a distinct continuation of medial fold. The families 
almost intergrade, as the confusion in the genera in Kirby’s catalogue 
bears witness. 
The larvae of the Dioptidae ( only known to me in Phryganidia ) 
have single Noctuidous setae. To derive the Pericopidae from them, 
we must suppose an independent wart formation analogous to that of the 
Apatelidae from the Noctuidae or the Eupterotidae from the Notodonti- 
dae, but simpler than either. 
Now as confirmatory evidence, we have in the moths the marked 
similarity in build and pattern of coloration j also a tendency in both 
families to the coalescence of veins 3 and 4, not seen in the Noctuidae 
and Arctiidae. The Noctuid habitus of the larva is also equally con¬ 
sonant with an origin from the generalized Noctuiform Dioptid larva as 
from any existing type of the Noctuidae. 
I think that we may conclude, therefore, that the Pericopidae are 
a family representing a specialized form of Dioptidae, with independent 
moving of vein 5 toward 4 and wart formation in the larvae. Their 
geographical distribution is also in favor of this conclusion, since, being 
confined to America, their origin from the strictly American Dioptidae 
is more reasonable than from either of the world wide Noctuidae or 
Arctiidae. 
