198 Mr. A. G. Butler's observations upon certain 



150 specimens, and discovers that the absence of six of 

 them, referable to only two gradations, would at once 

 leave the three species as sharply defined as any in the 

 genus, it naturally occurs to him to examine those six 

 specimens more minutely, and see whether they do not 

 exhibit differences inter se which point rather to hybridi- 

 zation than variation for their origin ; such I have found 

 to be the case, and, therefore, in the absence of positive 

 evidence of identity founded upon careful breeding, I do 

 not hesitate to regard the T. hecahc group, as represented 

 in Japan by three species. 



That the species of Terias are not necessarily subject 

 to great variation is evidenced by an examination of 

 series of the two other Japanese species, T. hetltcscba 

 and T. jcegeri ; of the first of these I have examined 

 twenty specimens from Nikko, which exhibit no variation 

 whatever ; of the second species I have examined thirty- 

 nine specimens, which only vary in the yellower or 

 redder tint on the under surface of the secondaries. 



Descriptions of the Japanese forms of the T. hecabe 

 group of Terias: — 



1. Terias mariesii, sp. n. PL vi. fig. 1. 



a. Male only differs from T. hecahc in its brilliant 

 lemon-yellow instead of dark gamboge-yellow colouring. 

 In this respect it shows no variation. The female 

 is of a sulphur-yellow colour, and is extremely rare.* 



b. Eather larger than the type, the border of the 

 secondaries of about half the width, and emitting short 

 black spurs upon the veins. Fig. 2. 



c. The border of the primaries slightly narrower, 

 especially near the external angle, the outer border of 

 the secondaries inconstant, the under surface with the 

 ordinary markings feebly indicated. Fig, 3. 



<L Like the type form {a) excepting that the black 

 border of the primaries is of little more than half the 

 width at external angle ; size very variable. Fig. 4. 



e. Similar to the preceding,, but with narrower border 

 to the secondaries. Fig. 5. 



/. Similar to e, excepting that the border of the 

 primaries is distinctly narrower towards the external angle, 

 and the border towards the costa not ane[ulated. Ficf- 6. 



* Only one female occurred in the collection, and none of T. anemone. 



