266 
MEMOIRS OF THE ^TATIOXAL ACADEMY OF SCIENCES. 
occurred at Providence on the wild cherry in September. Ilellins states that the e^gs of 
<7. vinula are 1.0 to almost 2 mm. in diameter, and that the larva at its first molt is not more 
than 7 mm. long, Possibly the first stage was not observed by Mv. Bridgham, and the following 
description should apply to the second. Compare also DyaFs detailed description : 
Ugg . — ‘‘Less than hemispherical — obtusely conoidaRthe base flat; minutely shagreened, color 
black; a little lustrous, but not shiny. Laid singly on either surface of the leaf.” (Dyar.) 
Cocoon . — Oval elliptical flattened, but central ai’ea well rounded; the edges broad and thin; 
spun of light drab silk; attached to side of breeding box or to bark of tree, and thus easily 
mistaken for an excresceuce on the tree; being a ca.se of protective mimicry. 
Larva: Stage II. — Length in all, 15 mm. September 4. Head only as wide as the body behind 
the middle. The filamental anal legs, or stemapods,^ as wo may designate them, are now more 
than slightly half as long as the body. Tlie horn like tubercles on the prothoracic segment ax^e 
slightly longer than in the second stage. The head and body are dark reddish brown above, the 
filamental anal legs with two broad, pale, greenish rings. All the other abdonunal legs are 
green; the green patch extends from the underside of the first abdominal segment back over the 
third to eighth pair of spiracles, and underneath to the end of the body. 
Stage II. — Length of body, 14 mm.; of stemapods, 7-8 mm., and of flagella, 3 mm. September 
11, Tlie head is rough and warty, the small warts bearing fine hairs. On the front towaixl the 
vertex are four pax^illiform, ixiliferous warts of the same size and shape as those on the prothoracic 
Xwqjections, and concolorous with the dark brown head. These spines are represented in the 
other species [C. occideutaiis) from the willow only by very minute warts, bearing long, tapering 
biistles. The prothoracic segment is very wide and large, the well-defined cervical shield very 
broad, and ending on each side in a large, stout tuberculated horn, bearing about twelve 
piliferous, i)axulIiform tubercles, there being a rude whorl of spines in the middle of the horn, the 
others growing out at the end. There are four coarse ])iiiferous warts on the hinder edge of 
the cervical shield. 
Along the body are scattered coarse ixiliferous warts, the dorsal four being arranged in a 
trapezoid. The stemapods are coarsely spinexl (more so than in C. occidenfalis). 
A peculiarity of the genus is the pair of very long papilliform iufraaual tubercles, situated 
under the suranal plate, and ending in two long, stiff, sliarp bristles.^ The suranal plate is long 
and narrow, well rounded, and the surface is provided with high papilliform, ixiliferous warts. 
Ill this sx^ecies the head and the x>i‘othoracic horns above and beneath are reddish brown, the 
latter in C. occidentalis being yellowish beneath, the two species by this mark being easily 
sei^ai^ated. 
The body is now more green on the sides, the green hue encroaching oh the back and ueaidy 
meeting ou the third thoracic segment. Only the fourth abdominal segment is wholly dark seen 
from above, and the green approximates high ux> on the sides of the sixth and sev^euth segments. 
Stage III . — September 17. Length of body, 19 mm, and of stemapods, 12 mm. The body is 
now much thicker than before. The iiead is now smooth, Avith no traces of piliferous warts or of 
hairs representing them. The head is noAV larger in proportion to the body aiul jialer red, 
JTlie term “.tails’’ or c.au<lai filaments is too vague for those highly modified anal legs; hence ^y^i proi)ose the 
term stemapoda or stemapods for those of Conira and Heterocampa. The derivation is Or. cTjjftay filament; tto/x, 
'iroddc, leg or foot. Mr. J. Hollins, referring to these organs in nuckler’s Larvie of the British BntterHies and 
Moths (Roy Soc., ii, 138), remarks “hut now through Dr. T. A. Chajmiau’s good teaching I regard them as dorsal 
appendages, somewhat after the fashion of the anal spines of the larvjo of the Satyridai.” This, I am satiafieil, is an 
error. After repeated comparisons of the filamental anal legs of Ceriira with those of TJeterocampa marihenia, and 
comparing these with the greatly elongated anal legs of young vnicoior as figured by Pox)cnoe, and taking into 
account the structure aud homologies of the suranal and xueanal flai>s, one can scarcelj' doubt that those of Cerura 
are modified anal legs. 
It should be also remarked that this was the view of Latreillo (Gen. Crust., et Insect., 1809, p. 219), who defines 
the genus thus: Lruca j^edibns analibus in caudam furcatam tmiisforniatin. 
2 The use of those T find explained hy Mr. Hellins in his descrix>tiou of the larva of C. hijida in Buckler’s Larvjo 
•of British Butterflies aud Moths, ii, xi. 142, as follows: “At the tip of the anal flap are two sharp points, aud another 
l^air underneath, which are used to throw the x^ellets of frass to a distance.” Similar clnngforks are very generally 
present in geometrid larvre, the infraaual pai^illiforin tubercles being well developed, though we have not seen 
them in use. (See also Dyar.) 
