Phylogeny of the Pierinee. 281 
costal nervure. In the very similar D. pasithoe it has 
been driven even from this position. 
Prioneris exhibits a condition very similar to that of 
Delias. The underside of P. thestylis closely corre- 
sponds with that of D. belladonna, and the resemblance 
applies to the precostal streak no less than to other 
features. In some species of Prioneris, as C. clemanthe 
and P. autothisbe, the precostal yellow is again ap- 
proached, and sometimes dislodged, by a greater or less 
amount of bright red, as in D. pasithoe, D. thisbe, 
D. crithoe, and other members of the former genus. 
Leaving the red patches and other features of the 
pattern of this region in Delias and Prioneris for dis- 
cussion at a later stage, we may pass on to the 
American genera Huterpe, Pereute, Leodonta, and Catas- 
ticta. In the two last-named the arrangement of light 
and dark markings corresponds generally with that in 
Delias and Belenois, and similar touches of deep yellow 
are mostly present in the same relative positions. One 
of these, usually to be seen on the costal margin, is 
clearly homologous with the precostal streak in the 
insects already referred to; in many specimens of C. 
mimbice, C. semiramis, C. toca, and others, it bears very 
much the same appearance as in the old-world genera 
above mentioned. It may be noticed in passing that 
in many instances, such as L. zenobia, L. dysoni, and 
C. anaitis, the yellow precostal streak is found sharing 
the precostal space with a greater or smaller amount of 
brilliant red, as we have seen to be often the case in 
Delias and Prioneris. The same struggle between 
yellow and red is visible in the genera Huterpe and 
Pereute. In H. tereas the space is shared, the red keeping 
to the inner, and the yellow, when present, to the outer 
side of the precostal nervure. In P. charops the space is 
usually all yellow; in P. auwtodice and P. leucodrosvme it 
is all red. In these two genera the other yellow marks 
are reduced in number or completely abolished; P. 
charops, however, generally has a conspicuous yellow 
patch between the costal and subcostal nervures which 
undoubtedly belongs to the series. 
In the genus Pieris, which is also American, some 
species, such as P. locusta and P. habra, show on the 
under surface of the hindwing a pattern which is 
evidently only slightly modified from that seem in many 
TRANS. ENT. SOC. LOND, 1894.—PART II. (JUNE.) a 
