Pierine Butter flies from Colombia. 43 



and Old- World forms of Myloihris ; no structural difference 

 which I have been able to discover is constant to all the 

 species. The fact that the New- World forms appear to 

 mimic Heliconidee, whilst the Old- World forms appear to be 

 mimicked bj the genus Phrissicra, would not of itself be 

 sufficient for a generic definition. In some of the New- World 

 forms the subcostal furca of the primaries is longer than in 

 some of those from the Old World, and vice versa ; in some 

 the lower discocellular of the secondaries is transverse, whilst 

 in others it is oblique ; the relative distances between the 

 subcostal branches also vary, but the main features of 

 Mylothris are retained by all the species. 



Myloihris Rosenhergi^ sp. n. 



^ . Near to M. lypera ; above milk-white, showing the 

 under- surface markings through the wing-texture ; primaries 

 with black apical third and costal border as in that species: 

 secondaries with the outer border black, irregularly indented, 

 distinctly narrower : below the primaries are the same as in 

 M. lypera^ but the secondaries are white, the basicostal band 

 very faintly tinted with sulphur, and the discal belt, which is 

 much broader than in M. lypera^ washed with bright sulphur- 

 yellow on its abdominal three-sevenths ; the orange streak on 

 the subbasal black band narrow and abbreviated, and the 

 external black border of about half the width of that in the 

 common species. 



Expanse of wings 64-68 millim. 



Two males, liio Dagua, Colombia [W. F. H. Eosenherg). 



Mylothris sulphuralis, sp. n. 



(^ . Also allied to M. lypera, but the apical black area 

 occupying only two fifths of the primaries and less distinctly 

 angulated or notched on its inner edge; outer border of 

 secondaries narrow, as in the preceding species : on the under 

 surface the narrower apical area of the primaries and the 

 sulphur-yellow, instead of orange, streak on the black sub- 

 basal (or basi-subcostal) band of the secondaries serve to 

 distinguish it from M. Rosenhergi. 



Expanse of wings 59-63 millim. 



Two males, Rio Dagua, Colombia ( W. F. H. Rosenberg) . 



Pieris kigaha. 



Pieris Mqaha, Realih-t, Proc. Ent. Soc. Phil. ii. p. 349 (1863). 

 Var. Pieris 7iotistriga, Butler and Druce, Cist. Eut. i. p. Ill ; Salvin 

 and Godman, Biol. Centr.-Amer., Rhop. p. 132. 



