Return to Publications List ◄ Next Page►
-16-
Subfamily OmaliinaeMembers
of this subfamily are easily known by the presence of a pair of pale mounds
('ocelli') on the surface of the head on or near a line drawn through the
posterior margin of the eyes. The elytra are usually longer than those of
most other staphylinids, those members covering about one-half of the
abdomen. Micralymma, an
exception, has very short elytra. Six genera are known with marine species,
but only three are included in the following key: KEY TO GENERA OF MARINE OMALIINAE I. Elytra about as wide as
long.........................................................................
Micralymma Elytra longer than
wide.............................................
.....................................................2 2. Head strongly produced in front of eyes.
....................................................Arpediomimus Head not strongly produced in front of
eyes.........................................................Omalium Macralymma
Cameron. This genus is not adequately described and so cannot be included in
the key. The single species M. punctiventris
Cameron (1945) is said to be maritime from New Zealand. Nesomalium
Steel. Four species from the seashore of Campbell Island and Auckland Island
in the sub Antarctic. Judging from the original description, this genus is
not separable from Omalium. Omaliomimus
Jeannel. Two species from the seashore at Campbell Island. Like Nesomalium this genus appears to be
inseparable from Omalium. Micralymma
Westwood. Members of this genus are confined to the northern part of the
North Temperate Zone. They are circumpolar in distribution. Five species have
been described from Siberia, Northern Europe, Greenland and Maine. They are
submarine in habits. Species of this genus are readily distinguished by their
very short elytra which cover no part of the abdomen. The British species M. brevipenne Gyllenhal is black, strongly
alutaceous and about 3 mm long. Arpediomimus
Cameron. This genus is said to be close to Omalium but has the head produced
forward of the eye for at least the length of the eye. Only two species are
known from the sub Antarctic island. A.
faulklandicus Cameron from the Falkland Islands is yellowish
brown and 4.5-5 mm long. It lacks ocelli. A.
kronei Kiesenwetter from Campbell Island is dark brown and 5-8
mm long. It has ocelli. The genus was reviewed by Steel (1964). Omalium
Gravenhorst. More than one hundred species have been described in this genus
mostly from decaying organic matter in the Temperate Zones. Four species are
known from seaweed from the British Islands and one from Pacific North
America. They are reddish brown and 2-4 mm long. Members of this genus are
particularly characterized by a longitudinal carina on the mesosternum. |