CHAP. XXI.] 
INSECTS. 
497 
North Temperate zone. It must be remembered, however, that 
in view of the immense geological antiquity of the existing 
families of Beetles, dating back certainly to the Secondary and 
probably to the Palaeozoic epoch, “ comparatively recent ” may 
still be of considerable antiquity. 
It is somewhat singular that North and South America have 
no genera exclusively in common. The connection between 
South America and Africa seems to be shown, — by the genus 
Psiloptera, the mass of the species being divided between these 
regions, with a few widely scattered over the globe; and the 
American genus Actenodes, which has one species in "West 
Africa. Somewhat allied, is the extensive genus Polybothris , 
strictly confined to Madagascar. The genus Agrilus is perhaps 
cosmopolitan, although no species of the family is recorded from 
New Zealand. Among the peculiarities of distribution we may 
notice, — the genus Sponsor, with 8 species in the island of 
Mauritius, 1 in Celebes, and 1 in New Guinea ; Ptosima , scat- 
tered between the United States, Mendoza in South Temperate 
America, South Europe, the Philippine Islands, and North 
China ; Polycesta, which besides inhabiting South America, 
North America, and Europe, has a single species in Madagascar ; 
and Belionota, which has 8 species African, 8 Indo-Malayan, 2 
Austro-Malayan, and 1 in California. The extensive genus 
Acmceodera, is most abundant in the warm and dry portions of 
the Palsearctic, Ethiopian, and NeaTctic regions, with some in 
the Andes and South Temperate America, a few in Brazil and 
the West Indies, and 1 said to be from the Philippines. About 
one-third of the genera (containing more than half the species) 
have a tolerably extensive range, while the genera confined to 
single regions contain only about one-fourth of the total number 
of species. 
It will, I think, be admitted, after a careful study of the 
preceding facts, that the regions and sub-regions here adopted, 
serve to exhibit, with great clearness, the chief phenomena of 
distribution presented by this interesting family. 
VOL. II. 
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