tter
are mostly allied to species found in Europe or in the other Atlantic
islands, while one is allied to an American species, and two are so
distinct as to constitute new genera. The following list of these peculiar
species will be interesting:--

CARABIDAE.

_Anchomenus aptinoides_ Allied to a species from the Canaries.
_Bembidium hesperus_ Allied to the European _B. laetum_.

DYTISCIDAE.

_Agabus godmanni_ Allied to the European _A. dispar_.

COLYDIIDAE.

_Tarphius wollastoni_ A genus almost peculiar to the Atlantic
islands.
{254}

ELATERIDAE.

_Heteroderes azoricus_ Allied to a Brazilian species.
_Elastrus dolosus_ Belongs to a peculiar Madagascar genus!

MELYRIDAE.

_Attalus miniaticollis_ Allied to a Canarian species.

RHYNCOPHORA.

_Phlaeophagus variabilis_ Allied to European and Atlantic species.
_Acalles droueti_ A Mediterranean and Atlantic genus.
_Laparocerus azoricus_ Allied to Madeiran species.
_Asynonychun godmansi_ A peculiar genus, allied to _Brachyderes_, of
the south of Europe.
_Neocnemis occidentalis_ A peculiar genus, allied to the European
genus _Strophosomus_.

HETEROMERA.

_Helops azoricus_ Allied to _H. vulcanus_ of Madeira.

STAPHYLINIDAE.

_Xenomma melanocephala_ Allied to _X. filiforme_ from the Canaries.

This greater amount of speciality in the beetles than in the birds may be
due to two causes. In the first place many of these small insects have no
doubt survived the glacial epoch, and may, in that case, represent very
ancient forms which have become extinct in their native country; and in the
second place, insects have many more chances of reaching remote islands
than birds, for not only may they be carried by gales of wind, but
sometimes, in the egg or larva state or even as perfect insects, they may
be drifted safely for weeks over the ocean, buried in the light stems of
plants or in the solid wood of trees in which many of them undergo their
transformations. Thus we may explain the presence of three common South
American species (two elaters and a longicorn), all wood-eaters, and
therefore liable to be occasionally brought in floating timber by the Gulf
Stream. But insects are also immensely more numerous in species than are
land-birds, and their