MEMOIRS OF THE >^ATIOXxVL ACADEMY OF SCIEIS^CES. 
75 
adapted for its life in a cell, being broad, obliquely truncated, the small antennm being protected 
by the flaring sides of the head, which is very solid, with numerous rugosities and small tubercles. 
The region about the mouth is remarkable. The clypeus and labrum are very narrow, the eye 
transversely elongated, with an impressed line in the middle. 
The eye-collar {mr, j).) is distinctly separated from the max- 
ilhe {7iu\). 
The two pieces (I}).) at the base of the maxillm may pos- 
sibly prove to be the labial palpi; if so, is the piece marked 1. 
the labium ? The two paraclypeal pieces or tubercles (jj.) appear 
to be the homologues of those in the Psychid:e. 
The pupm of this family are very extraordinary, but it will 
be seen that they are Piqxc incomj^letxv^ not Fnpcv libcrce, and 
prove that the family should stand much above the Microptery- 
^idm rather than below them, so far as regards pupal characters. 
The shape of the head of Hepialus musielinus and the 
reduced labium, with its 
two-jointed palpi and the 
still more atrophied maxillary palpi, are interesting. In H, 
tacomce the palpi of both paws are larger, showing that the 
process of reduction in Hepialus is a rather late one. 
The very primitiv^e, generalized shape of the thorax of 
the HepialidiC is noteworthy. In UepialKS miisielinvs the 
collar or prothorax is very much reduced, while in JL iavomw 
it is very long and generalized, as in Sthenopis and the Aus- 
tralian Ahantiades argenteus. The mesoscutum is consider- 
ably shorter than in R. tacomcv. In the latter species the 
metascutum is entirely divided by the large scutelluin, while 
in H. mustelimis it is only partly divided, the apex of the 
scutellum i)assing a little beyond the middle of the scutum. 
It is thus quite evident that Sthenopis is an earlier form 
than R. tacomw, and that the latter is more generalized, 
having undergone less modification than R. mustelimis. 
The genus Hepialus occurs in Australia, and that continent appears to be the original home 
of the fiiinily. In Ahantiades argenteus the antennae are tripectinate, and the labial pal[)i areveiy 
large; in Rectomanes fusca the antennae are 
bipectinated, but the labial palpi are much 
reduced, being scarcely visible, while On- 
copera intricata is remarkably modified; 
though the antennae are simifle, the eyes 
are very large, nearly meeting on the front, 
while the three-j,oiuted labial palpi are 
remarkably long and slender, extending 
upward, and the hind legs have a remark- 
able broad, flattened, curved pencil of hairs. 
It thus appears that on the Australian 
continent this interesting family, which may 
be a survival of Jurassic times and coeval 
with the marsupials, has branched out along 
■several lines of specialization, the most 
degenerate form being Hepialus, wliich has 
survived also in Europe and in Korth 
America, especially on the Pacific Coast. On the whole, however, as we have seen, it is not so 
generalized a group as the Micropterygidaj, a group common to Euroi^e and North America. 
ilpb Pf paraclypeal piece; mx., maxiU^e; 7nx. p, maxillary palpi. 
Pig. 36. — Head of pupa of Megalopyge (Lagoa), 
from Florida. 
