1890.] 
113 
[Packard. 
inal segment, and we know of no “caudal horn” in larval butter- 
flies, though it may have been noticed by others. In stage i of 
Telea polyphemus , however, the caudal horn is represented by a 
double, twinned, spiny tubercle. This fact would suggest that the 
Papilionidae may have descended from a type similar to, but more 
ancient than the existing Attaci. 
Papilio pliilenor in the first stage is less similar to the Attaci of 
the same stage, but still the dorsal thoracic tubercles are longer 
than the others, and multispinose, while those of the abdominal 
segments bear a single stiff seta. 
This specialization of the dorsal thoracic and eighth and ninth 
uromeral tubercles, in contrast with those on the intervening seg- 
ments, is noteworthy and is not noticeable in the larvae of the other 
families, even including the Nymphalidae ; on the other hand it is 
a characteristic feature of freshly hatched Attacid larvae. 
Judging by their freshly hatched larvae, the Hesperidae are the 
most generalized butterflies, as^heir imaginal structure also proves. 
The most highly modified group, judging by stage i of the larvae, 
is the Lycaenidae, since besides their onisciform bodies, the last 
three abdominal segments are in Tliecla liparops coalesced. The 
group is paralleled by the Cochlidiae (Cochliopodidae). 
On the other hand the Nvmphalidae in their freshly hatched state, 
especially Argynnis aphrodite and Speyeria idalia , bear a decided 
resemblance in the shape of the body and in the arrangement of 
the broad flattened piliferous tubercles to the first larval stages of 
the Arctians. We also notice in these two Nymphalids a slight 
specialization of the dorsal thoracic piliferous warts, since they 
bear two setae, those on the abdominal segments bearing a single 
one. The same obtains in stage i of Arctia virgo and Seirarctia echo , 
only the latter is slightly more specialized, since the thoracic dorsal 
tubercles bear from three to four setae. But the larva of Spilosoma 
virginica of the same age bears but two setae on the same tubercles. 
These facts- suggest the origin of the Nymphalidae from an ancient 
group more like the Arctians than any other ; at all events, that 
the group originated from moths whose larvae were setose. It is 
noticeable that in the freshly hatched Arctians the hairs are finely 
spinulate, while those of the early stages of Rhopalocera are not 
so, being represented as simple. 
So far, then, as our present imperfect knowledge of the early 
stages of the higher Lepidoptera extends, we seem warranted in 
PROCEEDINGS B. S. N. H. VOL. XXV 8 FEBRUARY, 1891. 
