( xii ) 



specimens, including the type, both females, have hitherto been 

 known to science. 



Mr. Loafs series did not seem to faAour the opinion that 

 had been held that Teracolus evayore, as described and figured 

 by Kkig, was the dry-season form of T. yerburii, Swinh. It 

 appeared from this and other evidence that Mr. G, A. K. 

 Marshall was right in dissociating the two forms. The weak- 

 ness of the reasons given for the contrary view had lately been 

 pointed out by Col. Yeibuiy. 



With regard to the general question of Seasonal Dimorphism, 

 a point that deserved notice was the greater intensity and 

 greater persistence of the cryptic dry-season coloration of the 

 under surface, which often characterizes the female sex. This 

 might be illustrated from among Mr. Loat's specimens ; but 

 the principle was of wide application, and was operative in 

 both hemispheres. In the genus Teracolus especially, the 

 '' wet-season " female often retained some of the " dry-season " 

 garb, and in certain cases (as in T. jmellarls and T. phisadia) 

 the female could scarcely be said to have a " wet-season " 

 phase at all. The significance of these facts lay no doubt in 

 the special need for protection experienced by the female sex. 

 Prof. Poulton had lately given strong grounds for believing 

 that on tlie whole concealment was a more eflicacious means of 

 defence for moderately distasteful forms than the display of 

 warning colours, especially when the pursuit was keen ; and 

 the instances here adduced seemed to show that it might in 

 some cases be of advantage for the female of a given species to 

 remain cryptic in the wet season, even though the male should 

 assume brighter colours with the advent of a more copious 

 supply of insect life. An interesting parallel with the seasonal 

 changes in Precis antilupe and F. archesia, so carefully worked 

 out by Mr. Marshall and Prof. Poulton, was furnished by the 

 Central and South-American I'roterjAct pyrisitia, Fabr. (a 

 Pierine form allied to Terias), with what is doubtless its dry- 

 season phase, ]'. (jiindJachia, Poey. Here, as in Precis, the 

 dead-leaf appearance of the under surface in the dry-season 

 form is enhanced by the falcation of the forewings and the 

 development of " tails." These changes of shape are found 

 in the gaudlaclda form of both sexes, but are intensified in 



