78 
tremities of two pair of legs, are visible. It is certainly very rare for 
even one pair of legs to reach this point in Papilio, and I know no 
instance of an exposed femur therein. In some Hesperids the girth is 
loose and the tips of the third pair of legs are exposed beside the wing 
apices, a feature that does not occur in true butterflies. The fourth 
difference between the pupae of Ephyra and Papilio lies in the frequent 
opening of closed incisions on dehiscence in Papilio ; this does not occur 
in Ephyra. 
In taking Papilio as the simplest form of the true butterflies, and 
therefore as nearest to the Hesperids, and in regarding the other fami¬ 
lies as derivatives from Papilio, I desire to be understood merely as 
meaning that Papilio still closely represents the primeval butterfly 
when it had become truly a butterfly as distinguished from a Hesperid, 
and as regarding the other families as having been derived from this 
primeval form, and not from Papilio itself. The pupa of this primeval 
form possibly differed from that of Papilio in having a single instead 
of a double “ nose-horn,” but no doubt Papilio very closely resembles 
it. 
I may mention here that Scudder gives the names “ ocellar tubercle ” 
and “ ocellar prominence,” to what I have called “ nose-horn.” I have 
preferred the latter as a provisional colloquial name, because it involves 
no theory. The term “ tubercle ” is now so definitely appropriated 
(in Lepidoptera) to certain larval structures, that one does not choose 
to use it in the case of pupae, unless one wishes to suggest that the 
pupal tubercle represents the larval tubercle, as is certainly the case 
in some pupae of Tjneina and others, where their disposition and 
possession of hairs is identical in larva and pupa. In the butterflies, 
the “ocellar tubercle” is, more probably than the reverse, not identical 
with a larval tubercle. As to “ ocellar ”—the position is in front of 
the eyes, and it no doubt serves for the protection of the eyes, as well 
as of the rest of the head; perhaps even more for the protection of 
the bases of the antennae than of the eyes. But, assuming an ocellar 
site for the nose-horns of Papilio, is it certain that the nose-horn of 
Pieris is the same structure, conjoined in the middle line ? In many 
pupae there may be seen, between the double nose-horns, two minute 
prominences, which are possibly those that are developed in the Pieridae. 
These may be seen in most Vanessids, and, in such a pupa as Do- 
ritis, where the nose-horns are so short that their existence might 
be disputed, there are between them, two very distinct tubercular emi¬ 
nences. The front of a butterfly pupa has, in fact, an inner and an 
outer pair of eminences. Is it certain that the inner pair does not form 
the “ nose-horn ” in some cases ? If it does, it would not properly be 
termed “ocellar.” It is perhaps of more importance to note that the 
eyes are dorsal structures, whilst the nose-spines are ventral. 
From this original form the other families branched off. 1. Par- 
nassiinae ; this did not progress very far beyond Papilio, and is sometimes 
included in the Papilioninae. 2. Pieridae; and along with them 
Nymphalidae, the latter leaving the Pieridae, whilst only the earliest 
forms of the latter had been evolved. 3. Lycaenida. 
- In each of these groups, the lowest forms agree with the primeval 
butterfly in the movability of the 5th and 6 th abdominal segments, 
but, whilst the others progressed, more or less rapidly, to forms with com- 
