2 10 MEMOIRS RATIONAL ACADEMY OF SCIENCES. vol. xii, 



Stage IV: Molted July 11-12. Length 40 to 45 mm. This differs but little from Btage III. The head is of the 

 same color as in the three previous stages, and about half as wide as the body. The segments are rather more angular 

 above than before. The prothoraeic segment is yellow in front; the tubercles are small, and of the same yellow tint. 

 All the other tubercles, both dorsal and lateral, are orange-red; the dorsal tubercles have on the outside of the base, and 

 extending nearly half way tip, a bright spot with a decided pearly color and luster; this spot is wanting on the infraspiracular 

 tubercles. Most of the bristles are black broadly ringed with white, or white at the base, and on the distal half. The 

 median dorsal tubercle on the eighth abdominal segment is still distinctly seen to be double, being bilobed at the end, 

 each lobe or subtubercle bearing about four white setae, one of them black. 



Along the sides of the body project long white hairs. The spiracles are orange-brown, as before. The suranal plate 

 is edged with flesh-pink, and the anal legs are bordered behind with the same smooth flesh-pink margin The thoracic 

 legs are reddish amber, black at their ends. The middle abdominal legs are green; the plantaa livid purplish; above 

 the planta is a dark patch, bordered above with yellowish. 



Stage V: Molted July 22-24. Length 60 mm. It now scarcely differs from the preceding stage. The silver tint 

 on the outside of the base of the dorsal and subdorsal tubercles, and on the upper side of the base of the infraspira- 

 cular tubercles, is a little more distinct than in stage IV, as in the latter stage the second and third thoracic dorsal and 

 subdorsal tubercles are more orange than those on the abdomen, which are deep coral-red; but in some of stage 

 IV the thoracic ones are coral-red. 



The head is reddish chestnut, and is the same in hue as in stages I to IV. The prothoraeic segment is edged with 

 yellow, the pale yellowish lateral stripe as in stages III and IV. The spiracles are deep orange-red. The segments are 

 now convex and almost angular, more so than in the other native forms of this group, unless we except A. luna. 



One of this brood began to spin and had completed the exterior of its cocoon by August 1. 



The object of the purplish edging on the suranal plate and anal legs was impressed upon me while observing a large 

 full-fed caterpillar resting by a short leafstalk, the leaf having been broken off so as to be a quarter of an inch long and 

 curved. In color and shape it exactly resembled the purplish edgings of the suranal plate and legs, and thus added to 

 the protective resemblance to a leaf and its stalk. 



A fine large T. polyphemus was observed at Providence, September 27, on the chestnut. I was struck with the 

 resemblance of the outline of the creature's back — the segments being angular so as to render the body serrate, each 

 tooth-like form of the segment surmounted by a tubercle and long hair — to the serrated edge of the leaf, each of the teeth 

 ending in a long hair. It is not improbable that the ancestors of Telea, Actias, and others with angular segments, may 

 originally have fed on trees with such serrated leaves, and that later they adopted as their more usual food plant such 

 trees as the oak, in which the edges of the leaves are either smooth or simply lobed. 



Recapitulation of the more Salient Ontogenetic Features. 

 A. Congenital Features. 



1. The setae (bristles) of stage I but little longer than the tubercles, and both truncate and distinctly bulbous at tip. 



2. A slight but distinct differentiation in size and color of the dorsal tubercles, those of the 3d thoracic and 9th abdominal 



segments being of the same size, and larger than those on uromeres 1-7, and of a deeper yellow shade. (Stage I.) 



3. The homologue of the "caudal horn" is distinctly double, and more deeply divided than in any other American 



genera of Attacinae; each fork about as long as thick. (Stage I.) 



4. Abdominal legs each with twenty-four crotchets (a larger number by 6 to 8 than in the other genera), stage I. 



5. Each abdominal segment (uromere) with a lateral pair of transverse black slashes in stage I. 



6. The two tubercles in stage I on the suranal plate slender, papilliform, and approximate. 



B. Evolution of later Adaptational Characters. 



1. The lateral pair of black transverse stripes on each uromere nearly or quite disappear in stage II. 



2. The segments more convex and angular in stage III. 



3. Appearance of a yellowish lateral oblique stripe connecting the lateral tubercles of the lower and upper row, in 



stage III. 



4. Appearance of the pale purplish edging of the suranal plate and anal legs, in stage III. 



5. Appearance in stage IV of the pearly spot on the outside of the dorsal tubercles. 



The generic characters are mostly assumed in stage III. 



TELEA AURELIA Druce. 



Telea aurelia Druce, Biologia Centr.-Amer. , Tab. 83, fig. 3. 

 [Telea aurelia Druce, Ann. Mag. Nat. Hist. (6), IX, p. 278 (1872).] 

 Telea aurelia Kirby, Syn. Cat. Lep. Het., I [p. 934], 1892. 



Imago. — One 6* . Judging solely by the figure of Mr. Druce this seems to be only a climatic 

 variety of T. polyphemus, differing from that species only in markings. On the fore wings the 

 basal line is darker, the dark shades of the northern form being intensified. The ocellus differs 

 in having the dark outer ring heavier and wider, and within it the discal space is shaded with 

 brown to the basal fine. The middle of both wings is darker and the extradiscal fine common 



