Article beginning on page 281.
Psyche 6:281-282, 1891.

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PSYCHE.
THE BOMBYCINE GENUS LAGOA, TYPE OF A NEW FAMILY. BY A. S. PACKARD, PROVIDENCE, R. 1.
In its general appearance the larva
of Lagoa is in some respects intermedi-
ate between the Cochliopodidae and
the Liparidae. It resembles the former
group in the short thick body; in the
head being concealed by the prothoracic
hood ; and in the venomous spines.
On the other hand it resembles the
Liparidae in the hairy body, the hairs
being finely plumose, a peculiarity of
more common occurrence in the Lipa-
ridae than in the Cochliopodidae.
As regards the cocoon this is inter-
mediate in form and texture between
that of Orgyia, etc., and the Cochlio-
podidae, but it more closely approaches
that of the latter; it varies somewhat in density in different species, being usu- ally quite firm and dense, like parch-
ment, nearly as much so as in those of
the Cochliopodidae, and also approach-
ing them in shape, being oblong-cylin-
drical, oval, contracted at the anterior end, and with a separately-spun lid,
closing the front end. As Dr. Lintner
has shown with many interesting details, "The lid is woven by the caterpillar
separately from the rest of the cocoon,
and is not a section cut from it after its completion." Ent. contr., ii. p. 142.
The pupa is much like that of Lima-
codes, etc., the integument or cast cuticle being remarkably thin, and after the
exit of the moth the antennae and legs,
as well as the wings, are free from the
body; while the latter is split both
down the back and along the under side
to the end of the thorax. Moreover
when the moth escapes, the pupa-skin
is left with the head and thorax project- ing out of the end of the cocoon.
As regards its imaginal or adult char-
acters it is also intermediate between
the two families mentioned. In the
short stout body and short broad wings
it has the habit of a Limacodes rather
than of such Liparid genera as Por-
thesia, etc. In the shape of the an-
tennae and palpi it is about as near the Liparidae as the Cochliopodidae.
In respect to the denuded head, Lagoa
is much more like Euclea than the
Liparidae. The clypeus is rather long
and narrow, similar in shape to that of
Euclea, though rather narrower, and is
thus more like that of the Cochliopodids than that of the Liparidae, represented
by Orgyia and the European Porthesia
chrysorrhaea, whose denuded heads I
have examined. The epicranium and
occiput taken together (on the median
line of the body) are about one third as long as the entire clypeus.
As regards the venation, Lagoa is




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decidedly nearer Euclea and other Coch-
liopodids than the Liparidae (I have ex- amined the venation of Orgyia and
Parorgyia) .
Lagoa has the same wide
costal region of the fore wings as in
Euclea, that of the Liparidae being very narrow ; the five branches of the sub-
costal vein are thrown off in nearly the same manner as those of Euclea and
Limacodes. The discal veins and ori-
gin of the independent (6th subcostal)
are almost precisely as in Euclea, and
the four branches of the median vein
are also similar in their mode of origin, and unlike those of Orgyia and Paror-
gyia.
In the hind wings, as in the Cochlio-
podidae, there are ten veins, in the Lip- aridae only nine; there are but two
branches of the subcostal vein, the
third branch being detached, so that
there are two independent veins, one
arising from the anterior, and the other from the posterior discal vein. In the
Liparidae mentioned there is no inde-
pendent vein. The four median vein-
lets have the same peculiarities in their mode of origin as in Cochliopodids and
the same differences from the Liparidae. To sum up : in the superficial char-
acters of the imago, and in having ab-
dominal legs in the larva, Lagoa resem-
bles the flat, scale-like Liparidae, but in all its essential characters, those of the egg, of the larva, pupa, and imago, it
belongs with the Cochliopodidae, except
in the matter of the presence of abdomi- nal legs in the larva. On this account it seems fairly entitled to be regarded as
the type of an independent group.
We
may regard it as a generalized, ancient
group of Cochliopodidae, and refer it to a subfamily Lagoinae, or we may boldly
remove it altogether from either of the
two families mentioned and consider
the genus as the representative of a dis- tinct family and designate the group by
the name of Layoidae. This on the
whole seems to us to be perhaps the
most judicious course to pursue. At
all events the insect is plainly enough
an ancient, ancestral, or generalized
form. It is a Cochliopodid with larval
abdominal legs.
It lays eggs like those
of Limacodes, etc. ; its head in the larval state is concealed from above by the
prothoracic hood ; its larval armature is more of the Cochliopodid type than Li-
parid ; so are the pupal characters and
the nature of the cocoon ; and the shape of the important parts of the head, and
the essential features of the venation, are overwhelmingly Cochliopodid. Under
these circumstances we feel justified in regarding Lagoa as a most interesting
ancestral form, and as affording argu-
ments for considering the Bombyces as
a whole as a generalized and ancestral
group, and as epitomizing the other
higher lepidopterous families.
The genus is peculiar to North, and
South America, and may rank with
such forms as the colossal sloths, and
certain American vertebrate survivors
of middle Tertiary times. In some re-
spects it is intermediate between the
Saturniidae, especially the higher At-
tacinae and the Cochliopodidae,




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