MEMOius or THE :natio2sal academy of sciences. 269 



■white; cxtrahiiKiluy line of Jive close, Uirfje hliick duls. ilir line iiitc'rrai)tcil iis if a dot on the 

 subcubitul fokl Iiad dropped out. Tlie black median liaiul niin.suaHij hrund and straight on each 

 side, with a distinct, firm, bhick edge on each side, especially within, and tlic band is thickly dusted 

 with white scales. A hea\-y outei- i)ai-allel lino close to the band, slightly sinuous, beginning' on 

 the inner edge and ending on the tirst cubital venule. A distinct scallo))ed white extradiscal 

 line, edged with black on each side, and an inner taint dusky line between it and the discal s{)ot, 

 the latter being elongated and distinct. The usual subapical triangular patch extends backward 

 larther than usual, being continuous with the outer of the extradiscal lines. JIarginal black dots 

 distinct. 



Hind wings white, a large diffuse discal dot, nuirginal black dots distinct; a small dark patch 

 ou internal angle. Underside of fore wings dusky, the outer edge of the wings a little wliiter ; the 

 white extradiscal line appears through. Hind wings white, witii a large diffuse discal o\al mark 

 and distinct dots. 



Expanse of wings, S 30 mm.; length of body, <5 14 mm. 



This line species is known by the broad black band, dusted with white, an*t distinctly edged 

 with black within and without; by tlie extrabasilar line of five large crowded dots, and by the 

 distinct white scalloped broad extradiscal line. Lintner says that in respect to the extrabasilar 

 row of tive dots it does not differ from aqnilonaris, but thus far 1 have not seen an example of the 

 latter with more than four dots, the row not being so crowded. 



Larva, Stage II. — Length of body, 11 mm. ; of steinapods, 8 mm. It differs from the foregoing 

 species of the same stage in wanting the frontal tubercles of the head, which is paler, and in the 

 h)nger and slenderer prothoracic horns, the latter having smaller spines; it is also yellow 

 beneath. The siiiues on the stemapods are finer. There is more yellow on the sides of the body, 

 the yellow extending along the sides of the stemapods. 



Stage III. — Length of body, l.j mm.; of stemapods, -1 mm. It differs from the third stage of 

 Cerura borealis iii the longer cervical shield and the shorter horns, so that the shield is more 

 normal iu shape, being as usual in many caterpillars. The piliferous warts over the body are a 

 little larger, while the dorsal reddish saddle-like spots are more deflnitely lined with deep red. 



Larva. — ^Leugth when fully grown, l.lio to the fork of the tail. Bodj' slightly enlarged in 

 front and somewhat compressed. In about the middle of the prothoracic segment is a prominent 

 projection on each side, the body sloping from these down to the rather small head; there is but 

 little sloping from the back to segment 9; from this there is a rapid sloping to the anal segment, 

 this ending in the two usual caudal filaments; when withdrawn these are a little more than a 

 ciuarter of an inch long, but may be extended to three-quarters. Clear bright greeu, sides spotted 

 with clear purple brown, the sjjots round the stigmata and at the base of the thoracic and abdom- 

 inal legs the largest. The back is marked witli lilac, varying in shade, and arranged as follows: 

 From the two small contiguous tubercles on the back of joint ^^ to the head is a somewhat 

 diamond-shaped sjjace, the broadest part at the subdorsal tubercles ou the prothoracic segment. 

 From the tubercles ou this segment to those on the next tlie lilac is bordered by bright brownish 

 purple with a white line; outside of this, in the middle of this diamond, is a little green shading. 

 From the tubercles on the second joint from the head to the end of the body is another i)arti- 

 colored space, lighter than the anterior one. This gradually expands so as to include the 

 stigmata on segment 7, then decreases iu width to the anterior part of the anal segment, 

 expanding a little in the middle of this, but contracting again at its posterior part. The lilac of 

 this is like the first, considerably suffused with greeu on the back, and is bordered with brownish 

 purple and white, though the colors are a little lighter posteriorly. These two dorsal i)atches are 

 not continuous, but are separated ou the second segment by a distinct though small patch of 

 green. The posterior projections are mostly brownish purple, though with somewhat greenish 

 annulations, and when extended a ring of white near the extremity. Head dark lilac. Previous 

 to the last molt the tubercles on the prothoracic segment ('-joint 1") were covered with little 

 spines (French, Can. Ent., xiii, 144.) 



Food plant. — Willow. 



Habits.— The caterjiillars of this moth were found feeding on willows (Salix nigra) hy Trof. 

 G. H. French, at Carbondale. 111., from September 9 to October 5. The moths began to appear the 

 following season from April 30 to June 3. In Maine it occurred ou the willow throughout August. 



