268 BUTTERFLIES 



Europe and America. The species, however, are 

 all extinct. 



One would hardly anticipate that creatures so 

 dehcate as butterflies could be preserved in a 

 recognizable state in deposits of hardened mud and 

 clay. Yet not only is this the case, but they are 

 generally preserved in such fair condition that the 

 course of the nervures and the color-patterns of 

 the wings can be determined, and even, in one case, 

 the scales may be studied. As a rule they are so 

 well preserved that we may feel nearly as confident 

 concerning their affinities with those now living 

 as if we had pinned specimens to examine ; and 

 generally speaking, the older they are the better 

 they are preserved. 



There is, to be sure, no great difference in their 

 age. Aix and Florissant are probably both 

 oligocene, and in any case can differ but slightly 

 in age. One of the butterflies from Aix, Collates, 

 comes from beds a little lower than the others and 

 may be looked upon as probably the oldest butter- 

 fly known. These two oligocene localities share be- 

 tween them a dozen butterflies, not to mention a 

 caterpillar from Aix which has been considered 

 that of a butterfly. Rott, the next oldest (lower 

 miocene), has furnished but one butterfly; and 

 Radoboj (middle miocene) the remaining three. 



