MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 125 



the tubercles on the sides of the bocly also heint;' decidedly shorter. whil(> the anal legs are laroer. 

 with a wider, dark, g-ranulatcd area on the outside. The hody is also thicker and heavier, while 

 the head is paler. 



It is noticeable that in this form, as in the Attacina?, there is a great inci'ease from one 

 stage to another in the size or bulk of the body, while the head does not increase in a correspond- 

 ing ratio. 



SUMJLAUY OK THE CHIEF OXTOGEKETIC FEATURES. 



A. — Conge II 'did cIik meters. 



1. In .stage I there are three pairs of veiy long dorsal deeply forked tlioracic horns, nearly 

 half as long as the body. 



2. A similar median spine on tiie eightli abdominal segment, with one about half as long- 

 on the ninth. 



3. The abdominal segments are transversely Ijanded with black. 



4. The lateral spines on the abdominal segments bifid and nearly as large as the subsimple 

 dorsal ones. 



5. Body pale chestnut brown; head light reddish. 



6. The spiracles minute and difficult tn detect, as they are situated in one of the transverse 

 black bands. 



B. — Evohitiiin of Inter adnptatlonol cJiar((<-fer'<. 



1. The forks of the larger dorsal spines disappear at the end of stage III. 



2. The dorsal thoracic spines become recurved in stage III. 



.3. The dorsal thoi'acic and caudal horns become much shorter and stouter in stage IV, when 

 the characters of stage V (and last) are nearly assumed. 



■4. In stage II the dorsal spines on the prothoracic segment begin to grow shorter and stouter. 

 5. In stage II the large horns begin to be less deeply forked. 

 G. The transverse black stripes disappear at the end of stage II. 



7. The dorsal and lateral spines on abdominal segments 1-7 ai-e much smaliei- in propoition 

 in stage III than in stage II. 



S. Toward the end of stage III the colors of the body become more conspicuous and variable. 



9. In stage III the spiracles become particolored and veiy conspicuous. 



10. The dorsal thoracic and the caudal horn become nuich shorter in stage IV, and not 

 forked at the tip. 



11. The hairs become long and abundant in stage IV. 



1'2. The body in stage IV becomes nuicli stouter antl heavier than before, while the head has 

 not gi'eatl}' gained in size proportionall\'. 



Food j)latiis. — Oak, button wood, bass wood, maple, honey locust, wild cherry, sweet gum, 

 sassafi'as, elm, sycamore, beech, chestnut elder, horn beam, birch, alder, white pine, spruce, 

 cedar, cypress, juniper, (Beutenniiiller). Sometimes injurious to trees, in Central Park, New 

 York (E. B. Southwick). 



Hah'dx. — The transformations of this moth were first described by Han-is, but the earlier 

 stages were first fully described by Mr. Lintner in his Entomological Contributions No. H. 

 Though usually feeding on the white pine in the New England States, where we have seen it in 

 the breeding cages of entomological friends, it also feeds on the oak, button-wood, etc., and will 

 eat the leaves of the chestnut. It is too rare to l)e of any economical importance, but will always 

 attract the attention of lovers of tine, rather rare in.sects. The moth lays its eggs in the northern 

 States late in June, hatching in about a week or ten days; the larva, according to Lintner, molting 

 at least four if not five times. A local name for it in Rhode Island is "custard moth." 



I have found the pupa at Cordova, j\Ie.\ico, in March, buried in the earth. 



Varietlex: Mr. Doll has kindly shown me a variety of the larva from Brandt Lake, in the 

 Adirondacks, in which the body is green. The Adirondacks larva has longer, more prominent 



