344 



transverse band. Discal spots of the secondaries much smaller than in 

 the male, and more rounded. 



Expanse of wings, cf 4 in. ; $ 4.9 in. Icf, 1 ?. 



The cocoon is double ; the outer coat being an oblong oval, pointed 

 at the upper end ; dark ashy-brown, with little patches of silvery silk, 

 and with an irregular, knobby surface. It is attached longitudinally 

 to the side of a twig. The inner cocoon is of a regular oval at both 

 ends, and closely woven upon the outer coat, except at the upper end, 

 where the point of the outer cocoon extends above the inner one. 

 Among about twenty cocoons, there seems to be scarcely any varia- 

 tion. 



Length of cocoon, 1.80 to 2.15 in. ; diameter, .6 to .8 inches. 



All the cocoons* were found, during the fall and winter, upon or 

 near an extensive bog covered with low bushes. They were mostly 

 attached to Nemojxmtlies canadensis and Rhodora canadensis ; a few 

 were found upon Kalmia angustifolia and maple, and one upon a 

 larch. The larvje undoubtedly feed upon the first two plants, and 

 perhaps upon the others ; but the cocoons were always where the larvae 

 might have fed upon the Nemopanihes or Rhodora. 



The imagines appeared May 24 and 29. 



This species differs materially in color fi'om S. Cecropia. The male 

 has the antennas, palpi, thorax, and legs much darker. The short gray 

 band on the hind part of the thorax is not found in ^. Cecropia. The 

 discal spots of all the wings are white instead of dull red, with a white 

 centre. The transverse bands of both pairs of wings are white instead 

 of dull red, bordered internally with white. It wants the broad white 

 band so conspicuous on the anterior border of the secondaries of S. 

 Cecropia^ and also the reddish tints and markings near the apices of 

 the primaries. 



The female differs from the female of S. Cecropia in having the 

 palpi, thorax, legs, and abdominal rings dark brown, or almost black, 

 instead of dull red. The discal spots of the primaries are linear, ob- 

 scure, and parallel to the transverse band, instead of broad, conspicu- 

 ous, and parallel to the costal border. The discal spots of the seconda- 

 ries are small, and almost round, instead of large and somewhat trian- 

 gular. As in the male, it has the white on the hind part of the thorax, 

 and wants the white on the anterior border of the secondaries, and 

 also the red on the apices of the primaries, on the discal spots, and on 

 the transverse bands. 



* This species seems to be infested by an unusually large number of parasites; 

 since, out of more tlian twenty cocoons, I liave succeeded in raising but three, 

 nearly all the rest having- been destroyed by ichneumons and other parasites. Its 

 remarkable rarity is, perhaps, due to this fact. . 



