114 THE entomologist's RECORD. 



Klectroponera, 1, allied to Ectatuiiniia. 



Nothomyrmex, 4, allied to Tetramorium. 



Stiphromyrniex, 1, allied to Pristomynnex. 



Parai)iera}ioplus, 1, allied to Meranoplus. 



Ermeamertts, 1, allied to Myr))dcaria. 



Protaneuretiin, 1, allied to Aneuretna. 



Paraneuretus, 2, allied to Aneiiretua. 



PJiopalomy) mex, 1, allied to Plaf/iolepis a,nA Myrmelachista. 



Prodiiiiorplioniyrinex, 1, allied to Dimorphowyrmex. 



Glaphijyoinyrinex, 1, allied to Formica. 



Thi/oiiiyniiex, 2, allied to Ap/toinomyrinex. 



2. Of uncertain affinities : 



Electromyrmex, 1. Asyviphylomyrmex, 1. 



Agraecoinyrmex, X. Pity amy rmex, 1. 



Stigoniyniiex, 1. 



After careful reasoning from the evidence to be obtained from the 

 above lists, Wheeler regards the ant fauna of the Baltic amber to be a 

 mixture of the Pal^earctic, Indian, Malayan, and Australian faunas. 

 Most of the truly extra-European affinities were rare in the amber 

 forests, and the most abundant ants (apart from the two species of 

 Iridoiiiyrviex) belong to Formica and Lasius, which are the two domi- 

 nant European genera at the present time. 



" A pronounced tendency towards a supplanting of the Indian, 

 Malayan and Australian elements in the mixed amber fauna by Palae- 

 arctic elements is therefore very apparent as far back as the Lower 

 Oligocene times, although it seems to have been permanently accom- 

 plished only by the advent of the Glacial Epoch." 



It is difficult to decide whether the amber species co-existed as 

 members of a single fauna throughout the life-time of the amber 

 forests. The extent of these forests was very large, their southern 

 boundary reaching across central Sweden, through Finland and Estland 

 to Minsk and Tobolsk ; the adjacent sea covering northern Germany 

 and the region drained by the Vistula, Niemen, and Dnieper as far as 

 the Black Sea. The climate was sub-tropical, as is shown by the 

 vegetation preserved in the amber, and it is supposed that part of the 

 area at least was mountainous. It is therefore possible that different 

 ant faunas co-existed at different elevations. 



In the case of different species found in the same block of amber, 

 it is at least clear that such species did exist together at the same time. 

 Wheeler enumerates the following : — 



Iridomyrmex yoepperti with Dolichoderus tertiariiis. 



I. yoepperti with Nothomyrmica riidis. 



I. yoepperti with I. geinitzi. 



I. goepperti with Lasius schiefferdeckeri. 



I, goepperti with Dhiwrphoniyrmex aimectens. 



L goepperti with Fo) mica Jiori. 



I. geinitzi with I. savilaridicus. 



Lasius schiefjerdeckeri with Formica constricta. 



Formica Jiori with Camjionotus mengei. 



F. horrida with Leptothorax gracilis. 

 Even here the more abundant forms may have been spread over the 

 whole amber area, and persisted throughout its whole duration, and 



