The Ants of the Baltic Amber. 
11 
Pheidologeton , Oligomyrmex and Carebara). This explains why Mayr 
originally described E. antiqua as a Pheidologeton, and why Emery 
later assigned it to Aeromyrma , after he had discovered a species of 
this genus (A. sophice) in the Sicilian amber 1 ). It is, indeed, not 
improbable that species of Erebomyrma may still exist in the Old 
World tropics, just as a species of Carebara has recently been discov- 
ered by Santschi to occur in South America. The case of Erebo- 
myrma antiqua thus bears an intertsting resemblance to that of the 
Cicindelid beetle Tetracha carolina L. Until recently this insect was 
supposed to belong exclusively to America, where it ranges over the 
Southern United States, Central America, West Indies and South 
America (Chili and possibly Argentina), but Horn x ) has discovered 
a specimen of it in the Baltic amber. He regards the species of 
Tetracha, and especially T. carolina, as among the most ancient and 
primitive of the Cicindelidse, and it is clear that it must, like Erebo- 
myrma, once have inhabited the eastern hemisphere. In Order to 
account for its occurrence in the amber he resorts to the following 
hypotheses: ,,Wie die Bernstein- Tetracha nach dem preußischen Sam- 
land gewandert ist, bleibt eine andere Frage. Zwei Wege wären 
möglich: I. der eine direkt von Afrika aus (vielleicht über die 
egyp tische Landbrücke oder östlich davon, um dann auf dem umge- 
kehrten Weg von II nach Amerika zu gelangen); II. von Amerika 
aus über die nearktische und skandinavische Landmasse , was mir 
zum mindesten nicht unwahrscheinlich erscheint.“ It is clear that 
one might advance similar suppositions in regard to Erebomyrma, but 
for the present I deem it unnecessary to go beyond the facts, which 
show that both Tetracha and Erebomyrma were cosmopolitan genera 
during the Eocene and that their present restriction to the neotropical 
region is due to their later extinction in the Old World. A similar 
Statement would probably cover many, if not all, of the cases of sup- 
posedly close nearctic and neotropical affinities among the insects of 
the Baltic amber. 
Having thus excluded the ant-faunas of Africa and America from 
any demonstrable participation in the composition of the amber fauna, 
except in so far as these countries have several genera in common 
with the Eurasian continent, we may turn to a consideration of the 
relationship of the amber to the present Eurasian and Australian 
b Le Formiche dell’ Ambra Siciliana, etc. loco citato, p. 577. 
b Über das Vorkommen von Tetracha carolina L. im preußischen Bernstein 
und die Phylogenie der Cicindela- Arten. Deutsch. Ent. Zeitschr. 1906. Heft II, 
pp. 329—336. 
