Phylogeny of the Pierinee. 303 
yellow in the precostal space on the under surface of the 
lower wings. This, however, is usually confined to the 
inner division of the space.* Mr. Wallacet considers 
that Metaporia agathon forms with Pontia nabellica the 
fragments of an extensive natural group. He also 
points out the readiness with which the pattern of 
M. agathon can be traced through P. nabellica, P. soracta, 
and P. hippia, to its final disappearance in P. cratzxgi. 
In this range of species, to which may be added 
P. oberthiirvi, P. leucodice, P. belucha, and others, we 
recognise the now familiar phenomena of the emergence, 
establishment, and evanescence of a marginal and sub- 
marginal series of spots, together with a discoidal patch, 
formed out of relics of an original dark ground-colour. 
Another primitive Pierine feature, namely the per- 
sistence of dark ground-colour along the course of the 
nervures and nervules, is found throughout the group; 
and in P. crateegi survives the disappearance of almost 
every other indication of the original coloration. 
The line thus marked out ends with P. cratxgi; but 
in another direction there is little difficulty in linking 
Pontia with Hucheira, and so demonstrating the intimate 
connection with one another of the three last-named 
genera. Thus Pontia recalls Hucheira by the outline of 
its wings, especially the concave costal margin,t and in 
pattern P. nabellica shows no very great departure from 
the same genus. Buta more striking sign of affinity 
exists in the common larval habitation, which, though 
merely rudimentary in P. cratzgi, and belonging only to 
the early larval stages, is no doubt a degenerate or 
undeveloped form of the elaborate silken nest con- 
structed by H. socialis. Webs of a structure apparently 
comparable with the latter are made by Neophasia ter- 
lootit and an allied species mentioned (though not 
described) by Behr.§ The affinity of the two latter 
insects with the genus Pontia appears certain; and 
though Behr is perhaps wrong in making them con- 
* One specimen of J/. agathon in Coll. Brit. Mus. has a few 
orange scales in the outer division of the precostal space as well. 
+ Trans. Ent. Soc. Lond., 3rd series, iv., p. 313. 
+ Noticed by Staudinger and Schatz, who compare it to that of 
Parnassius, Exot. Schmetterl., Th. i1., p. 62. 
§ Trans. Amer. Ent. Soc., 1869,.p. 303; Proc. Calif. Acad. 
Sci., second series, vol. ii., 1890, p. 91. 
