12 
William Morton Wheeler. 
ants. For this purpose we may divide the amber genera into two 
groups : those which are today represented in Europe and Siberia and 
those either belonging to the Indomalayan and Australian fauna, or 
with more or less pronounced affinities to this latter fauna. To the 
first group belong the following 13 genera, with 44 species: 
Ponera (2) 
Monomorium (2) 
Stenamma (1) 
Aphsenogaster (3) 
Myrmica (1) 
Leptothorax (5) 
Dolichoderus (9) 
Liometopum (1) 
Plagiolepis (6) 
Prenolepis (2) 
Lasius (5) 
Formica (6) 
Camponotus (1) 
The remaining 30 genera and 48 species may be referred to the second 
group. Among these, however, there are certain genera, such as 
Prionomyrmex , Phytidoponera and some of the species of Iridomyrmex 
(e. g. I. geinitzi ), which show decided affinities to existing Australian 
forms, others ( Protaneuretus , Paraneuretus ) which are closely related 
to the Indian Aneuretus and still others (Vollenhovia, Parameranoplus, 
Enneamerus, Dimorphomyrmex , Gesomyrmex, Pseudolasius, Dryomyrmex) 
and several species of Dolichoderus , which are more like forms now 
living in the Malay Archipelago. This last fauna, however, comprises 
an admixture of Indian and Australian types and in this respect most 
closely resembles the amber fauna. But the aspect of the latter is 
peculiar, owing to the absence of the genus Polyrhachis and the very 
poor development of the genus Camponotus , both genera represented 
by a great number of species in the Malayan fauna. 
We must, therefore, regard the ant fauna of the Baltic amber as 
a mixture of what at the present day we are able to recognize as at 
least four different faunas, the palearctic, the Indian, the Malayan 
and the Australian, with a little more than 1 / 3 of the genera and 
nearly 1 / 3 of the species palearctic and the remainder belonging to 
Indomalayan and Australian types. The proportion of individuals in 
these different faunas will be seen to differ greatly if we omit the 
two dominant species, Iridomyrmex goepperti and I. geinitzi, to which 
belong more than half of all the specimens examined, for the genera 
represented by the greatest number of remaining specimens are Formica 
(1336), Lasius (1257) and Prenolepis (684), or a total of 3277 speci- 
mens of the 4961 left after subtracting the 6717 contributed by 
I. goepperti and geinitzi . It should also be noted that the single species 
of Dolichoderus (D. tertiarius) which is most like the living D. quadri - 
