MEMOIES OF Tm<: NATIONAL ACADEMY OF SCIENCES. 23 



Laps danger siguals — though later in life the brown shades and green tints, so like the green leaf 

 with its serrated, blotched, sere-patched edges, would often deceive the most observant of birds. 



In regard to the nutant.or movable tubercles, it may be observed that a slight motion 

 of these appendages may suftice to scare off an approaching ichneumon or Tachina. If most 

 insects have, as supposed by Exner and by Plateau, more imperfect vision than has formerly been 

 attributed to them, so that they are extremely nearsighted and only clearly perceive bodies when 

 in motion, then even slight movements of these tubercles, while the caterpillar itself was immobile, 

 would probably be sufiBcient to frighten a parasitic insect and deter it from laying its eggs on the 

 cateri)illar. 



GROUPING OF NOTODONTIAN LARVAE ACCORDING TO THEIR AFFINITIES AND ALSO THEIR 



ADAPTATION TO ARBOREAL LIFE. 



As is well known, the larv;p of this family vary greatly in form and ornamentation for a group 

 of such moderate numbers; and the following synopsis has been prepared in order to show this 

 great variety in as graphic a manner as possible: 



1. Body smooth, not hairy, with red and yellow spots. GlKphiain. 



2. Body smooth, moderately hairy. Datana. 



3. Very hairy, the body almost totally concealed. Apalelodes. 



4. Body smooth, hairless; with no humps or tubercles, of a noctuid shape; anal legs never 

 elevated; color green, with yellow lines, the latter sometimes edged with reddish; feeding less 

 consjucuously than any others of the t;imily. Xddata, Lophodonia, etc. 



5. Body with two dorsal tubercles; also hairy. Ivhthyura. . 



G. Body smooth, polished; a single hump, surmounted by a horn on the eighth abdominal 

 segment. Pheosia. 



7. Back 2-8-humped, serrate, body smooth, not brightly striped. N'otodonta, Iserice. 



8. Body smooth, gayly striped, eighth abdominal segment gibbou s. Edema, Dasylophia. 



9. Body smooth, with nutant tubercles on first and eighth abdominal segments; end of body 

 uplifted. Colors green with l)rown patches simulating dead blotches on leaves. Hmmrpax, 

 Schizura, and Xylinodes. 



10. Body with stout spines and with spiny tubercles on first and eighth abdominal segments. 

 Sell izn ra ii n ico rn is. 



11. Body smooth, tapering; anal legs normal, often with two prothoracic tubercles, enormous 

 in early stages. Heterocampa guttivlffa, biuiidata, and ohliqua. 



12. Body smooth, striped; anal legs normal. Heterocampd manieo. 



13. Body with two dorsal prothoracic tubercles; anal legs fllamental; each ending in an 

 eversible dagellum. Macrurovampa murtliesia. 



14. r.ody with two lateral prothoracic tubercles; anal legs fllamental, each ending in an 

 eversible flagellum. ('crura. 



15. Body doubly humped on the abdominal segments; fllamental anal legs. The Old World 

 genus Stauropiis. 



So far as I have gone in the examination of the structure of the moths, this succession of 

 genei-a roughly corresponds with the classiflcation of the family. Judging by the moths alone. 

 Datana stands at one end of the series and Cerura at the other. 



Perhaps Cerura has generally been placed at the end of the group because of its fancied 

 resemblance to the larva of Drepana, but this is deceptive, because the long caudal filament of 

 the latter genus is simply a hypertrophy of the suranal plate, and the anal legs themselves are 

 atrophied, while in Cerura they are enormously hypertrophied, probably owing to their active use 

 as deterrent appendages. 



SUMMARY. 



One would suppose that the two genera Nadata and Lophodonta, with the Old World genera 

 Pterostoma, Ptilophora, Drymouia, Microdonta, and Lophoi)teryx ' (of the two species L. cucullina, 

 ■which is humped on the eighth abdominal segment, connects with the plain- bodied L. carmelita 



' Tho first hirval stashes of the following genera are still nnkuown. and the author would be niueh indeliteil for 

 eggs or alcoUolie specimens of the larv:e of the tirst and later stages: EUida, Lophodonta, Drvnioiiia, Notodoiita, 



