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Indiana University Studies 
This, the typical subgenus of Cynips , seems confined to 
Europe and the adjacent Mediterranean shores of Asia Minor 
and Africa. There it is the only subgenus of Cynips repre- 
sented. Further collecting may show that the group extends 
eastward across the whole of Asia; but it is evident enough 
that the five American subgenera, altho they have had a 
common origin with European Cynips, are as distinct as their 
not inconsiderable period of geographic isolation would lead 
us to anticipate. The closest American relatives of the Euro- 
pean Cynips are the Pacific Coast subgenera Antron and 
Besbicus. 
European Cynips is known from eleven varieties which 
represent the geographic segregates of six species. The most 
unique of these, Cynips cornifex, is confined to a limited part 
of the Mediterranean area in Europe. The other five species 
probably range as far as oaks extend in Europe, and at least 
some of them occur in northern Africa and Asia Minor. Each 
of these five species was first described from central Euro- 
pean material; but each of them may also have a distinct 
northern variety (only three of which are described to date) 
and one or more Mediterranean varieties (only one of which 
is described!). 
Studies of the geographic distribution, the host isolation, 
and the phylogenetic origins of the European fauna cannot 
progress very far when they are based on as uniform an area 
as that which constitutes Central Europe, or on a single 
species of host, which is essentially the oak flora ( Q . Robur 
and its minor variants: Q, pedunculata, Q. sessiliflora, Q. 
pubescens, etc.) in Central Europe. In America we have 
found the comparative study of groups of related varieties an 
unsurpassed means of interpreting biologic phenomena. The 
Central European fauna may offer similar possibilities if it 
is compared with its adjacent faunas. 
It should be emphasized that the study of cynipid varieties 
must be based on insects as well as on galls. We have many 
cases among our American Cynipidae where the varietal char- 
acters are not evident from the galls alone, and the herbarium 
collections in vogue among European “Cecidologists” will con- 
tribute little toward phylogenetic studies until they are 
fortified by large series of insects representing (for the Medi- 
terranean region) each of the species of oaks or groups of 
closely related oaks involved. 
