Phylogeny of the Pierinee. 279 
soracta, however, it is well marked. Metaporia agathon 
and M. phryze, which resemble the last-named species 
in other respects, also show a deep yellow mark in the 
same situation; but in this instance it occurs only as a 
spot bounded outwardly by the precostal nervure, and is 
not prolonged as a streak along the costa.* Many 
genera present this mark in much the same condition as 
the species of Ganoris first referred to; of which good 
examples may be seen in Nepheronia thalassina, N. argia, 
the curious Herpenia eriphia, Pinacopteryx pigea and P. 
capricornus, Mylothris chloris and M. agathina (deep 
orange in these), Tatochila theodice, Glutophrissa mar- 
garita, Appias zelmira, Phrissura_ sylvia, Daptonura 
lycimnia, Teracolus icne, T'. regina, T. eris, ete. 
Looking back to Synchloe hellica, we find that the 
yellow precostal streak forms in that insect only one of a 
series of yellow marks, one or two of which partially | 
occupy each interspace. A similar condition obtains in 
many species of Belenois; see for instance DB. mesentina 
and B. tewtonia. On the underside of the hindwing in 
these species, the dark lines following the course of the 
nervures, and the dark markings belonging to the various 
series above described, are laid down upon a ground 
colour which is usually white or pale yellow, but which in 
many specimens is relieved here and there by streaks and 
touches of a deeper yellow or orange. One of these 
streaks occupies the costa, and is plainly identical with 
the yellow precostal streak in Synchloe, Ganoris, and the 
other genera named. Although in the species of Belenois 
just referred to, as in several others, this streak is easily 
seen to form but one member of a series, it is never- 
theless more constant and persistent than any of its 
companions. ‘I'his is evident in those not uncommon 
specimens of B. mesentinat in which the general 
ground colour on the underside of the hindwing 
takes on so deep a yellow tinge as to approach that of 
the yellow streaks and touches. In these cases all or 
some of the latter set of markings may cease to be 
separately recognizable; the precostal streak, however, 
is always the last to disappear. In certain species of the 
* A specimen of M. agathon in Coll. Brit. Mus. has, however, a 
few orange scales in the outer division of the precostal space. 
+ I.e., the form known as B. auriginea. 
