PROBABLE FOOD-PLANTS OF TERTIARY CATERPILLARS. 71 



another fragment possibly referable to Mjlothrites, and Pontia Freyeri, all de- 

 scribed by Heer. Two of the genera of these more recent beds contain repre- 

 sentatives now living in the same region; but none of the older beds have yet 

 furnished butterflies referable to modem genera. 



It is rather extraordinary that the upper Miocene beds of QHningen, Bavaria, 

 which, if we except the amber, have furnished almost more insects than all the 

 other beds of fossil insects of the world together, and which are more recent than 

 any of those, in which butterflies have been found, have yielded scarcely any re- 

 mains of Lepidoptera (one species) and none whatever of butterflies. 



PROBABLE FOOD-PLANTS OF TERTIARY CATERPILLARS. 



Of the five butterflies from Aix, two belong to the Oreades {Neorinopis 

 sepulta and Lethites Heynesii) the food of whose caterpillars at the present epoch 

 has invariably been found to be either Graminese or, occasionally, Cyperaceae. 

 Both of these groups are present in the deposits of Aix, the former being repre- 

 sented by ten species of Poacites, and the latter by a Cyperites;^ and it is 

 in the highest degree probable that these formed the sustenance of the Oreades 

 of that epoch. A third species {Pamphilites dbditd) belongs to the Astyci, a group 

 whose principal food is the same family of plants, Graminese, although some 

 species have been found also upon Althca, Malva and Lavatera (Malvaceae), Tri- 

 folium, Coronilla and PLespedeza (Leguminosaj), Plantago (Plantaginaceae), and 

 Maranta (Scitamineae) . Of these families the Leguminosaj only are found at 

 Aix, and in abundance, even including a plant doubtfully referred to Trifolium. 

 It is, however, far more probable that Pamphilites lived upon grasses; and it is 

 not a little strange that the Graminea;, the probable food-plants of three of the 

 five butterflies known from that fauna, were among the rarest of the plants; that 

 is, their proportion to the whole phanerogamic flora was about the same as now 



' Saporta. R«TiKion de la llore ile» gj-pDes d'Aix. Ann. 8c. Nat. [15] Bot., xv, 284. 



