SEXUAL DIMORPHISM IN Bl'TTKRKLIES. lOij 



throughout the journey, whenever there wslh a gleam oi: sun- 

 shine between the prevalent showers, the exodus of 

 ((•a tops ilia) florella and rhadia continued in one un- 

 interrupted stream. These butterflies were to be seen in 

 countless numbers, from tlie deepest and darkest valleys 

 through which the Orange River forced its way, up to the 

 highest peaks, 10,000 feet above the sea, am/ all were steadily 

 moving eastward. Sometimes one of them would stop to take 

 a sip from a tempting gladiolus, or even turn back a few 

 yards for that purpose ; but it would be only for a minute, 

 and then off he would hurry again, as if fearful of being left 

 behind by his comrades. I have noticed the same swarms in 

 the Transkeian country and also in the Cape Colony. In 

 the latter, I believe, other members of the Fieri dae were 

 concerned." The above records might be greatly added to ; 

 but they are sufficient to show that some of the Fieri use 

 take only a second place to the locusts as migrants. The 

 vastness of the range of such species as Terias hecabe, jL., 

 and its allied species (so nearly allied as to make it very 

 doubtful to my mind whether they should be recognized 

 as anything more than local or geographical races of one 

 species), of Catopsilia pomona, of C. pyranthe and 

 others, alone is sufficient to demonstrate their capabilities 

 as wanderers upon the face of the earth "^ . The Oriental 

 regions are particularly favourable to the spread of butter- 

 flies, being under the influence of the N.E. Monsoon for 



*I have referred to Melaiiitis leda, i., as one of the few species 

 other than those belonging to the Pierinse included in Dr. Dixey's list 

 of butterflies that exhibit irregularities in Seasonal Dimorphism. Like 

 most of the SatyrinaB it is, seemingly, a feeble flyer, yet the following 

 incident shows it is capable of sustained flight in spite of appearances to 

 the contrary. Mr. Trimen records in a footnote to page 117 of " South 

 African Butterflies ":—'' I captured a Melanitis (Gnophodes) 

 parmeno {DoubL) at sea about 190 miles due W. of Sierra Leone, and 

 saw two others of same species on the 24th of November, 1871 ; the day 

 was perfectly calm, but quite a number of Lepidoptera and other insects 

 came about the ship. I was much surprised to find such shade inactive 

 Satyrinffi as this butterfly and several of two species of Mycaletis 

 among the visitors from the distant shore." 



