SATTRIN^. 147 



tbrougli Melanitis and Parantirrhcea, The genera are structurally very closely 

 related to each, other ; but in addition to the structural distinctions, each genus 

 exhibits a distinctive style of coloration and markings, which though sometimes 

 difficult to define, is generally unmistakable to the experienced eye ; thus, in 

 Mycalesis, the underside almost invariably has a straight transverse band across the 

 middle of both wings, with a more or less prominent series of ocellated spots 

 beyond it ; in Lethe, the basal area on the underside is usually either irregularly or 

 not at all variegated ; while in Zophoessa it is usually ornamented with straio-hter 

 transverse lines ; in Hipimrcliia [Bumenis] and the allied groups the upner surface 

 is usually brown, variegated with yellowish brown ; in Aulocera the upper surface is 

 black with a white transverse common stripe; in Erehia [Paralasa] the upper side is 

 dark brown, sometimes with ferruginous patches and an ocellus at the apex of the 

 forewing; in Ypthima the upper surface is more uniform lighter brown, and the 

 ocellus at the apex in it and in Callerehia is always bipupilled. Many of the genera 

 comprise but a single species, such as Aiiadebis, Orinoma, Gijllogenes, and Paran- 

 HrrhcBa; others again have only one representative within Indian limits, such as 

 Zethera [Buploeamima], Pararge [Lasiommata], Erites, OEneis [Paroeneis], and 

 Bagadia, or only two or three, such as Goelites, Neorina, Bkaphicera, and Zipcetis ; 

 the genera which contain the greatest number of species, such as Mycalesis, Lethe, 

 and Melanitis, have been recently divided off into several groups, some of which 

 depend, as in the case of the divisions of [the old genera] Danais and Euploea, on 

 the presence and position of scent-pouches and tufts of hair on the wings of the 

 male insect." (de Niceville, Butt. Ind. i. 95.) 



Seasonal Dimoephism : — Mr. de Niceville in Proc. Asiatic Society of Bengal, 

 December, 1884, writes, " During the last nine years I have collected butterflies in 

 Calcutta, and have always noted the months in which I met with the different 

 species. In this way I became aware that certain closely allied species [of Mycalesis, 

 Melanitis, Ypthima, and Junonia?[ occurred at particular seasons only, and when 

 these species were grouped together according to the time of the year they were met 

 with, it became apparent that those which occur in the rains were strongly ocellated 

 forms, whilst those occurring at other seasons had the ocelli reduced to mere 

 rudiments, or were absent altogether. "Why the wet season should beget a genera- 

 tion of ' eyed ' butterflies, and the dry season a generation of ' eyeless ' forms, I am 

 quite unable to offer a conjecture. In addition to the absence or presence of ocelli, 

 some of these species present other seasonal difl'erences. In Mycalesis perseus and 

 M. milieus, on the underside in the rains generation the discal white line is very 

 prominent, it is obsolete in the dry season generation; and on the latter form of 

 M. mineus, the forewing is much more produced at the apex, making the outer 

 margin straighter. In the dry season form of Melanitis Leda the forewing is more 

 falcate, and the underside is not striated." 



u 2 



