in the pupe of Heterocerous Lepidoptera. 107 
paper, appears to refer to all that has been written on 
the subject, and it does not amount to much. 
My own observations are still very imperfect, and the 
subject, like that of the pups, is a large one, with room 
for a great deal of work. The best records of individual 
species I am acquainted with is that in Scudder’s 
‘ Butterflies of New England,’ a work which is a model 
in many other respects. 
I think one finds in the Adelide some indications of 
how the prolegs and their hooks were developed. If, as 
is perhaps hardly probable, they do not present us with 
the actual history of their development, they, by re- 
version or some other process, give us what are probably 
some of the stages. In Hriocephala (Micropteryx pars) 
there are no prolegs. In’ Nemotois (fasciellus) and 
Adela (rufimitrella) there are series of chitinous points, 
beautifully arranged in rows like the teeth of a shark, 
the larger in front, those in each row alternating with 
those in the next rows, and gradually getting smaller 
till they merge in the fifth or sixth row in the ordinary 
integumental points. In the ordinary position of each 
proleg there are two such sets of points facing each other 
along a transverse line (only the anterior set in segment 
10). In Incurvaria muscalella the prolegs have two rows 
of hooks, facing each other in this way along a trans- 
verse line. In Lampronia capitella the young larva has 
no hooks, but the full-grown larva has hooks placed in 
a circle, yet with gaps showing that they are still an 
anterior and posterior set. 
In Tortrices the row of hooks is usually double; that 
is, there are longer and shorter hooks, but they are 
always in one perfect row; but in other families we find 
that traces of the multiple rows of Nemotois persists. 
This is the case in Hepialus. In Sestide again the circle 
of hooks is flattened antero-posteriorly, and weak or 
wanting at the outer and inner ends, showing a rela- 
tionship to Incurvaria. 
The anal prolegs very rarely have more than the 
anterior half developed. In Hepialus the circle is fairly 
complete. 
The Crambide have hooks of alternate size like 
Tortria (as have other Pyraloids), Crambus often 
(always ?) has 3 sizes of hooks alternated in one row. 
Though it is outside my brief, I cannot help referring 
