24 William Mobton Wheeler. 



Kelikte bezeichnet werden. Diese Betrachtungsweise schlieCt jedoch 

 nicht aus, daB sich auch an manchen Stellen abseits von der Urbeimat 

 neue Genera differenziert haben konnen, die wir dann als Endemismen 

 zu bezeicbnen batten. So weit icb momentan die Sacbe iiberblicken 

 kann, scbeint mir jedocb in keinem Falle zur Erklarung der Ameisen- 

 verbreitung die Annabme groCer versunkener Kontinente, die einst 

 quer iiber die grofien Ozeane reicbten, notwendig zu sein; daB solche 

 Kontinente nie existierten, soil damit natiirlicb nocb nicbt be- 

 hauptet sein." 



Wbile I agree witb Handliesch tbat we need not, in tbe present 

 state of our knowledge of Formicid distribution, postulate tbe existence 

 of great sunken continents, and wbile I am willing to admit tbat tbe 

 family may bave originated in Eurasia, I am unable to lay mucb stress 

 on bis reasons for tbis latter assumption. In tbe first place, as I bave 

 partially sbown on p. 9, tbe number of cosmopolitan or even of 

 tropicopolitan genera in tbe European Tertiary is not great. Formica 

 is by no means cosmopolitan, and tbis genus as well as Aphcsnogaster 

 and Campo7iotus would very probably not be found to be ricbly re- 

 presented in tbe later Tertiary if tbe species referred to tbem by Heeb 

 and otber students of bis day were to be reexamined in tbe ligbt of 

 modern taxonomic definitions. In tbe Baltic amber tbere is only one 

 species of Camponotiis and tbougb tbere are tbree of Aphcsnogaster, 

 two of tbese are represented by only a few specimens. In tbe second 

 place, a basty preliminary examination of several tbousand ants from 

 tbe Florissant sbales of C.-olorado, wbicb are attributed to tbe Miocene, 

 indicates tbat tbe Nortb American Tertiary ant-fauna was by no 

 means as insignificant as Handlirsch seems to imply. As tbe existence 

 of tbese numerous fossils makes it very probable tbat tbere must bave 

 been ants in Nortb America during the Eocene, tbe migration of tbe 

 family from Eurasia, if it took place as Handlirsch supposes, must 

 bave antedated tbe beginning of tbe Tertiary at tbe latest. I deem 

 it advisable, bowever, to postpone furtber discussion of tbis subject, 

 till I can take it up witb fuller and more precise data in my work 

 on tbe fossil ants of Florissant. 



