44 
ZOOLOGICAL GEOGRAPHY. 
[PART III. 
intermingled in nearly equal proportions with forms derived from 
Tropical America; and the varying degrees of resemblances of 
the Chilian to the northern species, seems to indicate successive 
immigrations at remote intervals. 
Colenptera. — It is among the beetles of South Temperate 
America that we find some of the most curious examples of 
remote affinities, and traces of ancient migrations. The Carabidee 
are very well represented, and having been more extensively col- 
lected than most other families, offer us perhaps the most com- 
plete materials. Including the Cicindelidse, about 50 genera are 
known from the South Temperate Sub-region, the greater part 
from Chili, but a good number also from Patagonia and the 
Straits of Magellan. Of these more than 30 are peculiar, and 
most of them are so isolated that it is impossible to determine 
with precision their nearest allies. 
The only remarkable form of Cicindelidse is Agrius , a genus 
allied to the Amblycheila and Omus of bT.W. America. Two 
genera of Carabidse, Cascellius and Baripus, are closely allied to 
Promecoderus, an Australian genus; and another, Lccanomerus, 
has one species in Chili and the other in Australia. Five or six 
of the peculiar genera are undoubtedly allied to characteristic 
Palsearctic forms ; and such northern genera as Cardbus, Pristo- 
nychus , Anchomenus , Pterostichus, Percus, Bradycellus, Trechus , 
and Bembidium, all absent from Tropical America, give great 
support to the view that there is a close relation be- 
tween the insects of the northern regions and South Temperate 
America. A decided tropical element is, however, present, 
Tropopterus is near Colpodes, a Tropical and South American 
genus; Mimodromius and Plagiotelium are near Calleida, a 
South American genus; while Pachy teles, Pericompsus, Vario- 
palpus , and Calleida are widely spread American groups. 
The preponderance of northern forms seems, however, to be 
undoubted. 
Six Carabidee are known from Juan Fernandez, 3 being 
identical with Chilian species and 3 peculiar. As the island is 
350 miles from the mainland, we have here a proof of how 
readily insects may be transported great distances. 
