Packard.] 
100 
[May 7, 
Mr. Poulton has in an interesting and suggestive way 1 after work- 
ing out the ontogeny of Aglia tau , proceeded to show that the caudal 
horn of the early stage of Aglia is a specialized spine, and that the 
“/$ phingidce are a specialization of the group of Saturnian Botnby- 
ces, and that the following order represents the nearest affinity, and 
is an approach towards the expression of genetic relationship.” 
Sphinx. 
Acherontia. 
Smerinthus. 
Ceratomia. 
Lophostethus. 
Aglia. 
Ceratocampa (Attacus). 
Saturnia. 
He also remarks: “Prof. Meldola informs me that he has long 
considered that the caudal horn of Sphingidce is to be looked upon 
as a remnant of a general spinous covering. Wilhelm Muller 
(Sudamerikanische Nymphalidenraupen, pages 249-250) identifies 
it, in the most convincing manner with the dorsal tubercles upon 
the eighth abdominal segment of Saturniadae.” 
I was particularly interested in Mr. Poulton’s conclusions, having 
within the past two years returned to some studies on the Bombyces, 
which were originally begun in 1862 and 1863, and having accumu- 
lated a considerable number of ontogenies of our Attaci, Cerato- 
campidae and Hemileuci, also of our Notodontians as well as of 
other Bombyces, with the kind aid of Mr. Joseph Bridgham, who has 
not only reared many of the forms, but has made numerous faithful 
colored drawings for me. The large body of facts thus accumulated 
regarding the life-history of these forms, some of them peculiar to 
America, and a study of the head-characters and venation of the 
moths, illustrated by camera drawings, enable me to endorse nearly 
all that has been said by Mr. Poulton. I will only remark that 
while the Sphingidae probably descended from forms like the more 
generalized Ceratocampidae, there are some points in the imaginal 
characters which appear to forbid the idea that the} 7 have immedi- 
ately descended from Aglia. The shape and relations of the epi- 
cranium, of the clypeus, and especially the venation and shape of the 
wings, show a wide interval between the imagines of the Bombyces 
and Sphingidae, which is bridged over in a measure by the Agaris- 
1 Trans. Ent. Soc. London, 1888, 568, 574. 
