Dr. G. B. Longstaff's Bionomic Notes on Buttcrjlies. 663 



veloped, but in the other they are rudimentary or entirely 

 absent. With the absence of ocelli is often associated a 

 more angulated form of the wings, which are sometimes 

 tailed, while the whole under surface is often of a redder 

 colour, and the insect when at rest is cryptic, sometimes 

 resembling a dead leaf. Again, in many Pierines there 

 are also two forms, the one characterised by the black 

 markings on the upper surface being more pronounced 

 and sometimes by a suffusion or irroration of black scales ; 

 whereas in the other form there is an irroration of reddish 

 scales on the under surface, with or without reddish or 

 purplish markings.* Now these two forms have long been 

 recognised as occurring for the most part in the Wet and 

 Dry seasons respectively, though it must be admitted that 

 in the case of Terias and Caiopsilia the correspondence is 

 not nearly so close as in Mycalesis, Precis and Teracolus. 

 However, for convenience these are usually spoken of as 

 " Wet-season forms " and " Dry-season forms," or even for 

 shortness as " Wet " and " Dry." 



When at rest, with wings closed above its back, the Dry- 

 season insect is usually more cryptic than the Wet, resem- 

 bling in some instances red soil, in others a dead or 

 discoloured leaf. It is notable that the Dry-season form is 

 commonly more marked in the female sex. 



If among Neotropical butterflies similar pairs of forms 

 are met with, I propose provisionally to speak of them as 

 " Wet " and " Dry," and then to inquire to what extent 

 they are found in the corresponding seasons of the year. 



Calisto zangis, Fabr. (Jamaica). Although there is some 

 variation in the size of the ocelli on the under side of the 

 wings in my specimens, I am unable to divide them into 

 seasonal forms. 



Euptychia hermcs, Fabr., camerta, Cram. In the Wet- 



* In Gatopsilia, Gallidryas and Ixias tlte disco-cellular spots on the 

 under side of both fore- and hind-wings are usually larger with larger 

 white centres and altogether more cons|iicuous in the dry season. 

 Moreover, in Ixias dry-season specimens have on the under side of 

 the hind-wing a series of reddish, or purplish, post-discal spots, 

 which when fully developed have white centres (especially in 

 I.pyrene), and call to mind the similarly placed ocelli so well known 

 in the fFei-season forms of Mycalesis and Precis, and indeed they 

 are not unlike the rudimentary ocelli seen in " intermediate " 

 specimens of those genera, though they never attain to the com- 

 plicated " peacock-feather " pattern so characteristic of many 

 Nymphalidx. 



