HEER ON FOSSIL ANTS. 63 



(Eningen together I have examined 279 specimens, belonging to 55 

 species : from (Eningen 158 specimens of 28 species ; from Radoboj 

 119 specimens of 34 species. 



All the existing species of Ants, as is well known, present astonish- 

 ing swarms of individuals. We have in Europe only about 40 species 

 of Ants, and yet these creatures are amongst the commonest of insects 

 that in summer enliven hill and valley. This proportionate abun- 

 dance indeed existed also in the ancient world. On account of this 

 abundance of individuals, it is easy to collect individuals of the species 

 that have lived at Radoboj and (Eningen ; and hence we may consider 

 these 28 species from (Eningen and 34 from Radoboj as tolerably 

 well representing all the species of Ants then existing at these places ; 

 and we may be said to have before us a tolerably perfect collection, 

 from these localities at least, of the Ants of that period. Indeed we 

 may come to a further conclusion ; the Ants have always a very wide 

 extension, and most of the species living with us are found throughout 

 Europe. These 5^ fossil species, therefore, may generally and more 

 or less perfectly represent the Ants of Tertiary Europe. 



5. The Ants are of importance in the fifth place, in that they 

 readily afford us the most numerous data for the comparison of the 

 (Eningen and the Radoboj faunae. Both belong to the tertiary epoch ; 

 still it is not precisely determined whether they were quite contempo- 

 raneous or otherwise, and this question can be solved only by a strict 

 comparison of the plants and animals of both localities. Of Coleo- 

 ptera, Radoboj and (Eningen have only one species in common {Tele- 

 phorus tertiarius), of Hymenoptera also only one {Termes pristinus), 

 and of Orthoptera none. We must remember that these forms occur 

 at Radoboj only as a very few species, and that we are as yet ac- 

 quainted with a much smaller number of insects from Radoboj than 

 from (Eningen. On the other hand both localities, as we have already 

 seen, are very rich in Ants. Of the 34 species from Radoboj there 

 are only seven that occur also at (Eningen, being about \ (the pro- 

 portion of Coleoptera being y^g-, and that of Hymenoptera \). We 

 must here also notice, that among these 34 species there are eight 

 which, being males, can probably be placed in the other species (fe- 

 males), and consequently there remain only 26 species. Of the seven 

 species that are common to the two localities, one is lost for the same 

 reason, reducing the number to six ; and thus not qaite one-fourth of 

 the whole number of the species are common to Radoboj and (Enin- 

 gen, which may be considered as an e\ddence of the contemporaneity 

 of the two faunae. We have to bear in mind that Radoboj lies near 

 about 7° more easterly and 2° more southerly than (Eningen, and 

 that from this cause the existing fauna and flora of these localities 

 differ considerably one from another, Radoboj having a more southern 

 character ; and the same is the case with regard to the fossil charac- 

 ters of this locality. 



The family of the Ants increases at the Tropics to very numerous 

 species, and there occur in warm countries some peculiar genera, as 

 Atta and the large F oner a. These genera are found also at Radoboj, 

 and indeed it is here that they appear for the first time, but they do 



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