J96 THIRTIETH REPORT ON THE STATE MUSEUM. [84] 



Cerura borealis (Boisd) 



This is quite a different insect from the preceding, and need 

 not be mistaken for it, or any other species. It is figured in 

 Gurnets Animal Kingdom, London, 1836, vol. IV, pi. 98, fig. 

 5, as Dicranura borealis Bdv. The figure leaves no doubt of 

 the species intended. On the right wing of the illustration, 

 the five inferior nervular spots (see description below) are 

 faithfully depicted in proper position on the median nervules 

 (the two superior ones not shown). On the left wing the two 

 inner sinuses and the three outer of the mesial band are cor- 

 rectly represented in form, size and position. The absence of 

 the two costal black spots between the bands, and of some of 

 the extrabasilar ones, would indicate some imperfection in 

 the example figured. It is also well figured in Smith and 

 Abbot's Lepidopterous Insects of Georgia, London, 1797, p. 

 141, pi. 71, as Phalcena furcula believed by Smith to be 

 identical with the furcula of Europe ; but to this insect it 

 bears no greater resemblance than to O. occidentalis. 



It is characterized by its white head and collar, thorax in from 

 marked with a conspicuous transverse black line, abdominal 

 segments broadly banded with fuscous dorsally. Primaries 

 of a snow white ground color, a basilar black dot, followed by 

 four other nervular ones, forming an angular line ; a broad, 

 centrally constricted, well-defined, mesial band, of about the 

 same width on the two margins ; between this and the sub- 

 terminal band are ttoo distinct costal spots, and below these 

 on the nervules, seven black spots arranged in an oval, as 

 follows : the two inferior ones on the first median nervule 

 (vein 2). the two medial spots of the exterior four, at about the 

 inner third of the second and third median nervules veins 

 3 and 4; of the two medial spots of the interior ones, the lower 

 is at or just before the bifurcation of veins 3 and 4, and the 

 upper is on the discal cross- vein; the superior spot of the oval is 

 on vein 5, equidistant from the two superior medial spots below 

 it. The subterminal line is distinctly marked, and followed 

 by the subterminal band, reduced to a line as it crosses veins 

 3 and 4, but again expanding on the inner margin. 



Secondaries with a well marked discal spc-t, and with a broad 

 marginal band; the latter in some examples is obsolete. 



Expanse of wings: from 1.50 to 1.70 inch. 



Habitat. New York, Pennsylvania, Virginia, Georgia, 

 Missouri (Aug. 26, at light, Biley). 



