No. i. BOMBYCINE MOTHS OF NORTH AMERICA— PACKARD. 19 



interest to students of heredity. Several of the forms have received names, as rnelaina Gross, 

 cerberus Schultz, ferenigra Thierry-Mieg, ferecaeca Oberth., uniformis Oberth., etc. A race 

 from Japan has been described as japonica by Leech, while one from west China has been 

 named homora Jordan. The variety lugens Standf . is identical with ferenigra, according to 

 Jordan.] 



[The following general discussion of the affinities of Aglia appeared in Proc. Amer. Philo- 

 sophical Society, XXXI (1893), pp. 139-141:] 



Aglia tau, a connecting link between the Ceratocampidx and Saturniidx and the type of a new subfamily, Agliinx. 

 In this European Bonibycine moth we have surviving, side by side with the generalized Saturnia, a most interesting 

 form, which is a Ceratocampid in its earlier larval stages, the larva in its last stage and the moth being very near the 

 Saturnians, although it does not spin a cocoon, and should be regarded as a Ceratocampid. We could not have any 

 clearer demonstration of the origin of one family from another by direct genetic descent. 



The transformations of this form, originally figured in Duponchel et Gu6neVs Iconographie ' (Tome II), has been 

 more fully elaborated by Mr. Poulton. 



Having received, through the kindness of Dr. Heylaerts, a young larva of Aglia tau in its third stage, I have been 

 able to compare it with Eacles imperialis in its third stage, a thing Mr. Poulton could not do for want of specimens. 

 The resemblance between the two genera at this stage is most striking, although the fully fed larvae are so different, 

 Aglia passing at a single molt (the third and last, this larva only having four stages), from one family to another ! We 

 know of no parallel case, or at least of one so very striking and conclusive. 2 Thus the ontogenetic development of 

 this caterpillar epitomizes that of two families, whereas that of most Bombyces is simply usually only an epitome of 

 that of a subdivision of a family, or of a small group of genera. 



Aglia tau in its third stage differs from Eacles imperialis in its third stage in having a pair of dorsal "horns" on the 

 first and third thoracic segments, where E. imperialis has only minute ones on the prothoracic segment, while those on 

 the second thoracic segment are as well developed as those on the third segment; those on the second segment are 

 minute; all the ''horns'' are forked as in Eacles. The dorsal spines on the abdo m i n al are simple and minute, like 

 those on the second thoracic segment. The shape of the head and of the anal legs is much as in Eacles, but the suranal 

 plate differs st rikin gly in being produced into a rather large, spinulated spine, a feature not known to exist in any 

 Ceratocampids. 



It should be observed in regard to the large size of the prothoracic horns of Aglia, that those of Citheronia regalis 

 are quite well developed, being about two-thirds as long as those on the two succeeding segments. 



Upon examining the adult of Aglia, I find that its head and antennae are closely similar to those of Eyperchiria 

 [Automeris] io, and the Hemileucidae in general; the antennae form a close approach to those of H. io, as on careful 

 examination with a good lens a second branch of the pectinations of the male antennae can be perceived ; it forms a long, 

 separate branch, but is in the dead and dry specimens very closely appressed to the anterior main pectination. In the 

 venation of both wings Aglia shows a most unexpected resemblance to that of Eacles imperialis; like that and other 

 CeratocanipidEe and the Hemileucidae, having five subcostal branches, while in the Saturniidae there are only four, 

 the first one wanting in the latter family. 



Thus the moth belongs with the Ceratocampidae, while the larva after the last molt loses all its spines and becomes 

 very much like a Saturnian, perhaps of the type of Telea, though it is without tubercles or spines, and especially like 

 a smooth form, the larva of Attacus betis Walker, figured by Burmeister in his Atlas of the Lepidoptera of the Argentine 

 Republic. We therefore suggest that Aglia tau should be regarded as the type of a distinct subfamily of Ceratocampidae, 

 and thus the latter group may be divided into the two subfamilies Ceratocampinae and Agliinae. 



At present both from their larval and their imaginal characters, and in their spinning a cocoon we are disposed to 

 consider the Hemileucidae as a family closely allied to, though distinct from, the Ceratocampidae. 



On examining the European genus Endromis, we are disposed to think that the family Endromidae is a natural 

 one. It would, however, be a violation of the principles of classification to include Aglia with it. The two genera, 

 both as regards their larval and their adult characters, are quite distinct. I find that Endromis versicolora has the head, 

 palpi, and antennae and the hairy abdomen very closely like those of our Hemileuca maia, but the median vein of both 

 wings divides into four branches, and the subcostal vein of the four wings divides into five branches, as in H. maia 

 and the other Hemileucidae. Judging by the colored figures of the larva in European works, the larva of Endromis is 

 smooth, with a small retractile head, oblique bars, and a conical caudal horn. The group Endromidae is a branch of 

 the Bombyciue tree, parallel to but distinct from the Hemileucidae, and stands above the latter, connecting the group 

 and the Oeratocampida and Saturniidaj with the higher families of the Bombyces, in which there are four branches 

 of the median vein, all the families mentioned agreeing with the Notodontidae in having but three. In its general 

 shape, the small retractile head, the mode of coloration, and the caudal horn, the larva of Endromis appears to be 

 remarkably near the Sphinges. Buckley describes the cocoon as "composed of an open-worked reticulation of coarse 



1 Guenee states that after attaining its full size, " Elle se retire a la surface de la terre, entre des mousses et des debris de veggtaux qu'elle attache 

 avec de la soie, et elle s'y change en une ehrysalide grosse, courte, d'un brun fonciS saupaudre 1 de grisatre, et dont l'anus est termini par une faisceau 

 de pointes recourses." 



! Over 20 years ago, in 1863, when first beginning my studies on the Bombyces, my attention was attracted to the singular changes of Aglia tau 

 and I compared the young larva to the full-grown larva of Citheronia regalis and pointed out that the latter genus was an "embryonic form and 

 therefore inferior in rank to the Tau moth." (Amer. Naturalist, June, 1S70, and Our Common Insects, 52.) 



