JUAN VI N AS— THE WATERFALLS 197 



grown larvse of Thaumatoneura were found a few days later 

 which, transforming, confirmed the evidence as to their 

 identity. 



The males of both inopinata and pellucida were obtained 

 from the transformed larvae and a minute comparison of 

 the exuviae from which they respectively issued has shown 

 no differences that cannot be considered as due to slight 

 injuries received by each. This fact, together with the 

 lack of observable differences in the females caught pairing 

 with the males of inopinata and pellucida respectively, 

 seems to point to the conclusion that there is but one species 

 of Thaumatoneura after all, a species in which the females 

 are all colored alike, although showing a certain range of 

 variation in size and in the proportions of the hind wings, 

 but with two forms of males whose wings show the very 

 marked difference in coloration which originally led to their 

 being given distinct specific names. These are still useful, of 

 course, in distinguishing the two forms. That this view as 

 to the relations of inopinata and pellucida is correct can only 

 be definitely determined when, from the eggs of known 

 parents, both pellucida and inopiyiata offspring are reared 

 to maturity. 



The case of Thaumatoneura, on this interpretation, is 

 relatively rare, but a parallel is afforded by the North Amer- 

 ican butterfly Lyccsna (or Cyaniris) pseudargiolus, the jump- 

 ing spider Mczvia vittata, and certain Lucanid and Staphy- 

 linid beetles. The reverse case, where in a given species, 

 there is but one form of male and several forms of females, 

 occurs more frequently in insects, as for example in the 

 dragonflies of the genera Ischnura, Neurothemis and Ery- 

 throdiplax, and among butterflies of the genera Papilio, 

 Colias and Pamphila. 



Thaumatoneura, as far as known, is confined to Costa 

 Rica and Panama and appears to have no very close rela- 



