) 

 no. i. BOMBYCINE MOTHS OF NORTH AMERICA— PACKARD. 191 



from 400 to 500 of this species. He once remarked to me that the tail in the banded individ- 

 uals is on the whole inclined to be shorter than in the unstriped individuals. On the other 

 hand, he said, the pale thin green ones bred on leaves of the sweet gum (Liquidambar) have 

 very long tails, no bands, and the fore wings edged with reddish-pink. Are there food varieties ? 



Mr. Field informs me that in examples bred by him at Milton, Mass., bands appear after 

 emergence from the cocoon as soon as the wings expand, but that after about an hour they 

 disappear. 



[The following was evidently written by Dr. Packard at a different time:] 



Mr. A. G. Butler, Annals and Mag. Nat. Hist., fifth series, IV, p. 356, 1879, remarks as 

 follows concerning this form: 



"Linnaeus evidently confounded T. dictynna with T. luna; for although in the tenth edition 

 of his 'Systema,' he quoted Catesby's figure of the North American insect and Petiver's rep- 

 resentations of the same species as illustrations to his brief diagnosis, yet for the fuller descrip- 

 tion given in the 'Museum of Ulrica,' he quoted Clerck's 'Icones' first of all; and the figure 

 in the latter certainly represents the Mexican species, inasmuch as the wings are crossed by a 

 well-defined discal stripe. It is probable that both descriptions are taken from the northern 

 type." 



It would seem, since dictynna is scarcely a local race of luna, much less a "Mexican species," 

 that Linne did not confuse the two forms, for individuals with wings crossed by a well-defined 

 discal stripe, are Hable to occur anywhere, north or south, or in Central America.' 

 (2) Tropaea azteca Packaed, Guide to Study of Insects, p. 298 (1869). 



[The original description is as follows :] 



"In the museum of the Peabody Academy is a closely allied and undesciibed species from 

 the west coast of Guatemala, which we would call Actias azteca. It differs from A. luna on 

 its much smaller size, expanding only 3i inches, and in the shorter fore wings, the apex being 

 much rounded and with shorter veins, while the 'tails' on the hind wings are only half so long 

 as those of A. luna. It also differs in having the origin of the first subcostal venule much 

 nearer the discal spot than in A. luna, being very near that of the second subcostal venule. 

 It is whitish green, with markings not essentially differing from those of A. luna." 



Originally described as a new and distinct species, I have again examined the single 9 

 type specimen, which has been discovered in the collection of the Cambridge Museum, pre- 

 sented to that museum by the Peabody Academy of Science, Salem, Mass. 



It was described as quoted above as differing from A. luna in its much smaller size, and in 

 the shorter fore wings, the apex being much rounded, "while the 'tails' on the hind wings 

 are oidy half as long as those of A. luna." It is whitish green, with markings not essentially 

 differing from those of A. luna. What we then said regarding the supposed difference in the 

 venation does not now seem of much weight, as there do not seem to be any perceptible differ- 

 ences. 



A reexamination of the type has resulted in the following observations : The type of azteca 

 is similar in shape of wings and in the discal spots with their stalk to the summer form of an 

 ordinary T. luna from New York, but it has decidedly shorter tails than any specimen I have 

 yet seen, while the apex of the fore wings is much more rounded. There are no traces of a 

 submarginal line, as seen in var. dictynna. The discal ocellus of the fore wings is small and 

 narrow, in the center is a narrow lanceolate oval clear space, edged within with a pink semi- 

 circle, succeeded by a broader black crescentiform semicircle, containing a linear strip of pale 

 blue scales. It measures 4 by 3 mm. The stalk is well developed. The blue fine in the discal 

 ocellus of the hind wings is not distinct; the spot measures 4£ by 4$ mm. 

 Expanse of the fore wings, 9 90 mm. 

 Length of a single fore wing, $ 45 mm. 

 Breadth of a single fore wing, 9 26 mm. 



i [Dr. W. T. M. Forbes informs me that all the specimens of T. luna from southern Florida in the American Museum of Natural History are of 

 the dictynna type, and on the average quite different from the northern form. They have the banded wings and shorter tails, but differ from 

 Walker's account of dictynna in having more crimson color than the ordinary luna. This last character may be seasonal.) 



