758 THE BUTTERFLIES OF NEAV ENGLAND. 



graphical relations are almost precisely those of Eugonia mentioned above, 

 though the genus itself is far better represented today in Europe than in 

 America. They feed generally on Cruciferae, but these are plants of a 

 nature hardly admitting of preservation in a fossil state and are excessively 

 rare in the European tertiaries ; none have been found at Eadoboj whence 

 this butterfly comes, the most closely allied being a species of Tcrminalia. 

 The Parnassian is an interesting insect, belonging to a striking and rather 

 aberrant group. From its affinities to Thais it is called Thaites. Thais is 

 confined to-day to the Mediterranean district, within which Aix, its place 

 of deposit, belongs, and its allies are found, some in the same region, 

 some in China and Australia, and some in Alpine regions. It probably 

 fed on Aristolochia and while this genus has not yet been found at Aix, 

 it is found in other European tertiary deposits, and according to the Mar- 

 quis Saporta, the principal student of the fossil plants of Aix, "ce genre 

 devait y exister." When compared with Thais, the markings of Thaites 

 are seen to show an inferior character, indicating a clearly earlier type. 



There are left the two Hesperidae, — a family not represented ^in Amer- 

 ican rocks. One of these, Thanatites from Rott, belongs to the tribe Hes- 

 peridi, and is closely related to Thanaos, a genus found in the north 

 temperate zones of both hemispheres, but vastly more developed in the New 

 World, which has at least four times as many species as the Old, some of 

 them extending into the subtropical regions ; the adjacent genera are 

 purely American, although tropical or subtropical, and therefore Thana- 

 tites looks toward subtropical North America for its prevailing affinities. 

 Entirely the same is the case with Pamphilites of Aix, a butterfly belong- 

 ing to the other tribe of Hesperidae. The food plant of both these but- 

 terflies was very probably Leguminosae, which occur in abundance both 

 at Rott and at Aix. 



The allies, therefore, of nearly one-half of the European fossil butterflies 

 are to be looked for in the East Indies ; of one-third of them in America, 

 and especially subtropical America ; of the remainder at home ; but, as 

 among other insects and among the plants, there is growing likeness to 

 American types as we pass upward through the tertiaries. 



The American fossil butterflies, fewer in number, less varied in char- 

 acter, and all from one locality are more quickly reviewed. They all be- 

 long to extinct genera. Six of the seven belong to the Nymphalidae, and 

 all but one of them to a single tribe, Vanessidi, of the subfamily Nympha- 

 linae. Of these, three, Prodryas, Jupiteria and Lithopsyche, form a group 

 by themselves, more closely allied to one another than to any living forms, 

 l)ut having distinct affinities to certain butterflies of Central and generally 

 subtropical America. A fourth, Nymphalites, is related to them, though 

 not very closely, and it, too, finds closer relations among Central American 

 butterflies. The fifth, Apanthesis, is still farther removed and is related. 



