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CHAP, xxi.j INSECTS. 487
Palasarctic has 2, but none peculiar; the Ethiopian 13, with 11
peculiar ; the Oriental 8, with 3 peculiar ; the Australian 9, with
2 peculiar; and the Neotropical 15, with 10 peculiar. The
connection between South America and Australia is shown by
the latter country possessing 9 species of the characteristic
South American genus Tetracha, as well as one of Megacephala.
The small number of peculiar genera in the Oriental and Aus-
tralian regions is partly owing to the circumstance that two
otherwise peculiar Oriental genera have spread eastward to the
Moluccas and New Guinea, a fact to be easily explained by the
great facilities such creatures have for passing narrow straits, and
by the almost identical physical conditions in the Malayan portion
of the two regions. The insects of Indo-Malaya were better
adapted to live in the Austro-Malay Islands than those ef
Australia itself, and the latter group of islands have thus ac-
quired an Oriental aspect in their entomology, though not with-
out indications of the presence of an aboriginal insect-fauna of a
strictly Australian type. The relation of the Australian and
Neotropical regions is exhibited by this family in an unusually
distinct manner. Tetracha, a genus which ranges from Mexico
to La Plata, has 9 species in Australia ;
while Megace^phala has
2 American and 1 Australian species. Another curious, and
more obscure relation, is that between the faunas of Tropical
America and Tropical Africa. This is also illustrated by the
genus Megacephala, which has 4 African species as well as 2
South American ; and we have also the genus Peridexia, which
has 2 species in South America and 2 in Madagascar.
Several of the sub-regions are also well characterised by pecu-
liar genera ; as Amhlychila and Omus confined to California and
the Eocky Mountains ; Manticora, Ophrtjodera, Platycldle arid
Dromica, characteristic of South Africa; Megalomma ojiA Pogonos-
toma peculiar to the Mascarene Islands ; and Caledonica to the
islands east of New Guinea. The extensive and elegant genus
Collyris is highly characteristic of the Oriental region, over the
whole of which it extends, only just passing the limits into
Celebes and Timor.
The Cicindelidse, therefore, fully conform to those divisions of
Vol. II.—32