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habit and structure and the higher, cocoon-making forms, have 

 a tendency to overstep the usual behavior ot the Heterocera 

 and become day-fliers. Few occupations are so attractive 

 to the collector of Lepidoptera as the study of Hawk Moths, 

 from the size and beauty of the specimens. Comparative 

 studies are now needed; lengthy and detailed descriptions 

 of the different stages are scattered by various hands in our 

 literature, but they are undigested and to a certain extent 

 unused, if not in themselves useless. 



As compared with the Hawk Moths of other Continents, 

 the North American species suggest several points of interest. 

 And first, the ancestry and origin of the group may not un- 

 likely be determined in our fauna, as I have pointed out, 

 by the study of such oldfashioned Moths as are our Dryocam- 

 pians. The somewhat remarkable larva of Atreus plebeius, 

 found by me on Staten Island on the common Lilac, a 

 cultivated shrub, first led me to a suggestion of this origin 

 taken in connection with the larvae of Dryocampa, Anisota, 

 of which I found three species on oak, and of Eacles, which 

 I found on horse-chestnut. Already in 1865, I venture 

 (Sphingidae of Cuba, p. 5) to make some generalizations on 

 this head and subsequent studies have only confirmed my 

 belief that in North America are survivals of older groups 

 of Lepidoptera to be found, which will throw light upon the 

 genealogy of the present families. I draw attention on that 

 occasion to the larva of Ceratomia, and the late Benj. D. 

 Walsh, who wrote me some interesting letters at a later date, 

 has made some valuable remarks on the structure of the 

 larva of SpMngicampa, although his breeding experiments on 

 this species, liicolor, were defectively conducted as, years 

 ago, I fully explained. Later writers often overlook papers 

 issued some years back, a piece of inexcusable inattention. 



When we study the general distribution, it is seen that 

 the higher groups are rather fuller and better represented 

 in the Old World; while the gray, moth-like Splnnginae 

 maintain in the New World a larger number of forms. As 

 compared with the Asiatic, our representation of the family 

 is more sombre-hued. owing to the absence of a number of 



