134 MEMOIIIS OF THE NATIONAL ACADEMY OF SCIENCES. 



type of T. jocosfi. The liittcr is also more genenilly subocberous tliaii usual, and without a line on 

 the liiud wing. 



Kortlie op])ortiinity of examining" five alcoholic example.*; of tlie first stage of tins larva, I am 

 indebted to I'rolessitr Itiley; those of the last stage 1 liave e(jllccted from the ])oplar. Mr. II. 

 Edwards (Papilio, iii, 24) briefly de.seribes the second stage, and addti that it "feeds in conijjanies 

 until after the .second molt; the larvu' then separate and act indei)endently of each other."' 



The eggs of the normal form of this sjiecies (i. e., I. inclKstt) were received from Mr. W. N. 

 Tallant. of Columbus. Ohio. They were laid July -'() and the larva- hatched August 10 or 11. it 

 feeds at first socuilly on the aspen, eating out j)atches on the under surface of the leaf. 



Ufff/. — Diameter about 0.0 mm. Hemi.spherical, rather high; the shell is tliiii. white (the egg 

 is reddish just betore the larva hatches). The sliell under a Tolles lialf inch objective is seen to be 

 covered with minute jiolygonal cells which are tolerably distinct, with slightly thickened walls. 



Larva, Stage I. — (Hatched August 10-11. Described two days after hatching, and al.so from 

 alcoholic s]>ecimens of the same brood.) Length, .'^ mm. The body is rather long. cyliii(lri<-al, 

 head rounded, but little wider than the l)o(ly at first before the latter becomes filled out alter 

 eating a few days, as later it is no wichu' than the body; it is shining jet-black, and provided with 

 .scattered, long, stitt', tapering bristles. The i)rotlioracic and suranal plates are shining brown- 

 black. The former is moderately large, about three timl^s as broad as long, irregularly trapezoidal, 

 narrowing a little behind, and shows no signs of division into two halves; four hairs arise from 

 the front and four from the hinder edge. QMie piliferous warts on the thoracic as well as 

 abdominal segments are more or less conical, and none bear more than a single hair. The second 

 thoracic segment bears two minute median dorsal tubercles, one on each side of the median line 

 of the body, and smaller than those on the third segment, while the next one on each side of the 

 body is larger than the homologous ones on the third thoracic segment. The tubercles on the 

 second and third thoracic segments are arranged across the segment in a straight line, four of 

 them being visible on each side above. On the abdominal segments the tour dorsal tubercles are 

 arranged in a more or less curved line, the curve becoming more marked toward the end of the 

 body, until on- abdominal segment S the curve is almost semicircular. On the first abdominal 

 segment the two median tubercles are larger than any on the thoracic .segment, and arc larger 

 than the subdorsal and lateral ones on the segment in question, and are decidedly larger than the 

 Lomologous ones on the second to seventh abdominal segments. The four dorsal tubcr<'les on 

 segments l! to 7 are all of the saiue size, but the two on the eighth segment are nearly as large as 

 those on the first, -and are about twice as large as those on the seventh abdominal segment; on 

 the eighth segment, however, the subdorsal tubercles are nearly as large, but are narrower than 

 the two in the middle. This segment is slightly hiiini)ed. and bears a brown .spot surrounding the 

 bases of the two twin tubercles, and a sinular spot occurs on the first abdomiual segment. The 

 four dorsal warts on segment 9 are arranged in a trapezoid, the two in front being one-half as 

 large as the two behind. The upper subdorsal row of tubercles are i>artly connected by short 

 lines or streaks, and between this and the next row of warts lower down is a broken fine brown 

 hue, which is, however, almost obsolete. A fine nearly obsolete (or is it inci])ient ?) dorsal brown 

 line. In more advanced specimens the body is ])lainly stri])ed on each side with three interrniited 

 dark reildish lines. The piliferous tubercles or warts are dark brown, and give rise all over the 

 body to but a single hair. A pair of especially large long hairs arises from the second thoracic and 

 ninth abdominal segments. The hairs are long and slender, and though under a low power they 

 appear to be tapering, under a one tifth objective they are seen to be docked or blunt at the end 

 and some at least slightly but distinctly bulbous at the tip; they are also seen to be hollow and 

 truly glandular; tiie end apjiears to be Hattened; as seen sideways, the hairs appear to ta])er. The 

 hairs vary much in length, some being longer than the body is thick. An unusual, if not uiii(|ue, 

 feature, exce[)tional among bombycid larva' in the first stage, is the microscopic hirsiities clothing 

 the body. Under a one fifth inch objective the microscopic hairs are very short, quite uniform in 

 length, very dense, and ta|)er to a ])oiiit. 



The suramil i)late is distinct. l)lackish, nearly as long as broad, rounded triangular, and bears 

 on the edge eight jjiliferous warts of nearl.\' equal size, besides two arising from the surface, a little 

 in front of thc^ middle. The spiracles are round and reniaikalily small. 



