64 GEOLOGICAL MEMOIRS. 



not occur at (Eningen ; and Radoboj has absolutely a greater number 

 of species of Ants than (Eningen, although (Eningen is richer in other 

 insects, and although (Eningen Ants are much more frequently found 

 in collections. The above goes to prove the more southern character 

 of the Radoboj fauna. With this the flora also agrees ; for at Radoboj 

 three species of Palm (Flabellaria m«a?m«, Unger, Fl. Frei/eri,\JngeYj 

 and Ph(£nicites spectabilis, Unger), a Smilax, and a Ficus, occur in 

 connexion with other southern forms. The extinct fauna of (Eningen 

 is of a more southern character than what obtains at (Eningen at the 

 present time, and comes nearest to the existing fauna of the Mediter- 

 ranean ; but that of Radoboj is yet more southern, and indeed appears 

 to be somewhat subtropical ; but this also may be explained by the 

 more southerly position of the district. 



6. This brings us in the sixth place to a comparison of the fossil 

 with the existing Ants ; and here I will confine myself to a few im- 

 portant points. First of all I would observe, that the genus Myrmica, 

 which plays an important part in the existing fauna, some of its spe- 

 cies being the most abundant in the whole family, is but feebly deve- 

 loped in the fossil state. I have met with only 26 specimens (22 

 from (Eningen and 4 from Radoboj) belonging to 8 species. It was 

 therefore at that tim.e less plentiful, particularly at Radoboj, than at 

 present. On the other hand it occurs in two strikingly beautiful, 

 large species, Myrmica macrocephala and 31. tertiaria. The latter 

 of these was widely spread, since it is found at (Eningen, Parschlug 

 in Steiermark, and Radoboj. The former, on the contrary, occurs 

 only at (Eningen, but there it was the more plentiful species ; it ap- 

 pears for the most part to agree with Myrmica barbara, Fabr., of 

 North Africa. 



The genus Atta, as before remarked, occurs only at Radoboj, and 

 is represented by three, or if we deduct a male, by two species. One 

 of these resembles in general form and in the venation of the wings 

 the singular Atta cephalotes, Auct., which is plentiful in tropical 

 America, and there often penetrates in great swarms into the dwell- 

 ing-houses, and destroys all vermin, as flies, bugs, &c. The other 

 species may be compared with Atta destructor, Latr., occurring in 

 the south of Europe, which inhabits sandy places, and constructs an 

 entrance to its habitation in the shape of a tube or tunnel formed of 

 sand. The whole genus, with the exception of a single species found 

 in the south of France, is extra-European, and more particularly found 

 in the warmer parts of America. 



Of the genus Ponera one species (P. contracta, Latr.) is frequently 

 found with us, but it is a small, insignificant species. The warmer 

 parts of America, on the other hand, afford a number of fine, large 

 species. Three species occur at (Eningen, Radoboj, and Parschlug, 

 which for the most part remind us of these tropical forms, and one of 

 which appears to be closely related to Ponera apicalis, Latr. 



By far the majority of the fossil Ants belong to the genus Formica, 

 This is divisible into two groups ; in the one there is but one discoid 

 areola [Discoidal-zelle] in the venation of the vdng, and in the other 

 there are two such areolae. They differ also in their mode of living; 



