( cxviii ) 



r. viardi, pt/loiis aud apicalis the fimbriae are unusually long. 

 The disc in several of the species has an evident proximal 

 orifice; this in P. apicalis is exceptionally distinct, and is 

 furnished with a chitinous rim. Some of the ordinary scales 

 in P. marana are peculiar, being shaped somewhat like a 

 green fig, and heavily loaded with pigment. 



In Pieris p)hileta, more generally known as P. vionuste, the 

 scent-scales are numerous. They are much like those of 

 P. tithoreides and P. demopkile, but larger. The base is 

 rounded and somewhat narrowed ; the sides diverge towards 

 the apex, which is sharp. The disc is small, triangular, and 

 possesses an evident aperture. The fimbriae are rather long, 

 straight and distinct. 



Coming now to what I have called the second section of 

 Pieris, we find plume-scales of a very different type from those 

 just described. The laminae are exceedingly long and narrow, 

 with a more or less rounded base. The apex is seldom quite 

 so filamentous as in many species of Delias, but the general 

 contour and to a great extent the sculpturing of the lamina is 

 strongly reminiscent of that genus. A well-marked point of 

 difference, however, exists in the disc, which in this section of 

 Pieris is extremely small. A conspicuous peculiarity of the 

 assemblage now under notice is the localised distribution of 

 the scent-scales on the surface of the wing. If the male of 

 one of these butterflies, say P. phaloe or P. huniae, be ex- 

 amined, it Avill be seen, as has indeed been pointed out by 

 Dr. Butler, that the upper surface of both fore- and hind- 

 wing is divided between a smooth and a mealy or rough- 

 ened area, the difference of texture between the two being 

 on a naked-eye view very like that which is apparent on the 

 wings of male individuals of the genera Catopsilia and Calli- 

 dryas. In these species of Pieris, however, the roughened area, 

 instead of constituting a kind of border to the wings, occurs in 

 the form of streaks which follow more or less closely the 

 cov;rse of the nervures, ending in a tapering extremity as the 

 margin of the wing is approached or reached. These rough- 

 ened or mealy streaks, which are easily visible to the naked eye, 

 mark the situations where the plume-scales are to be found. 

 Here these structures, which ai e very easily detached, are so 



