1899.) 



GROTE — GKNEALOGIOAF. TREES OF BUTTERFLIES. 



149 



lower than the other butterflies, would be a mistaken assumption. 

 The opposite view, that the Hesperiades represent ancestral forms 

 of the Papilionides, would be the more tenable, were it not contra- 

 dicted by the fact that the Papilionides possess an exclusive charac- 

 ter in the short, downwardly curved anal vein of the fore wings. 

 The diphyletism of the two groups becomes thus apparent and pre- 

 vents further comparison. The Papilionides and Hesperiades are 

 parallel developments and neither represents an ancestral stage of 

 the other. 



In a review of the genealogical trees of the butterflies hitherto 

 published, it will again make the subject clearer if we commence 

 with the diphyletic tree, first published by me in 1897. I choose 

 here the elementary first sketch, already printed in the Proceedings 

 OF THE American Philosophical Society for January, 1899, giv- 

 ing dotted lines to show the diff"erent points at which it has been 

 presumed that the Papilionid line may have intersected with the 

 Hesperid. In the trees published by me in the Butterflies of Hilde- 

 sheim and in Natural Science, I endeavored to intercalate the minor 

 divisions upon this basis. The three culminating family groups, the 

 Parnassiidse, Pieridse and Lycsenidae, have, in certain forms, the 

 Radius of the fore wings specialized by the reduction of the branches 

 to four, and sometimes even three in number. In the three lower 

 groups the Radius always remains in a generalized, five-branched 

 condition. Most of the six family groups of butterflies retained have 

 been elsewhere subdivided into families; but, for the sake of sim- 

 plicity, the names are here used in their older collective sense. 



Fig. I. Diphyletic genealogical tree of the Butterflies, Grote, iSgy, 



A 



Papilionides 



B 



Hesperiades 



Parnassiidas 

 Papilionidae 



Pieridae 



I Nymphalidse 



Lycsenidse 



Hesperiadae 



PKOC. AMER. PHILOS. 800. XXXVIII. 160. K. PRINTED JAN. 29, 1900. 



