460 Scientific Proceedings, Royal Dublin Society. 
It will be seen that of the thirty-three genera included in this 
sub-family, nine are peculiar to the Nrorropican Recron, and all 
of these appear to be confined to the Brazilian sub-region. The 
Chilian sub-region seems, like Australia, Polynesia, and New 
Zealand, to be entirely without Agrionines. The genus Hete- 
rina ranges through the Mexican sub-region into the Sonoran, 
and as far as Merriam’s Transition Zone, and its range is over- 
lapped by that of the Holarctic genus Agrion, which comes south 
as far as Florida and Texas. Hence, so far as this sub-family is 
concerned, the Sonoran Rezeion, without characteristic genera of 
its own, is merely neutral ground between the Neotropical and the 
Holaretie; there is no more reason for annexing it to one than to 
the other. 
The Eruiorian ReGion is comparatively poor in this sub- 
family. Of its four characteristic genera, two (Umma and Sapho) 
are peculiar to West Africa; and one (Phaon) ranges into Mada- 
gascar ; the fourth (Libel/ago) is specially noteworthy as the only 
instance in the sub-family of discontinuous range; it has ten 
African species, and one in the Philippines. 
The Orienrat is by far the richest region in Agrionines. 
Thirteen genera may be reckoned as peculiar, including the large 
and important Lhinocypha, which just transgresses the limits, 
having two species in Thibet, and three in Papua. Two other 
genera (Matrona and Caliphaea) are common to the northern 
Oriental and southern Holarctic (Manchurian). In the Hot- 
Arctic Recion we have four peculiar genera—FEpallage in the 
Mediterranean sub-region; Archineura, Mnais, and Paleophlebia 
in the Manchurian, Archinewra being confined to China, and the 
two last-named to Japan. Then there is the typical genus 
Agrion or Calopteryx spread all over the Holarctic and Sonoran 
Regions. 
The distribution of the genera of this sub-family indicates a 
high degree of specialisation in the fauna of the different regions. 
The most notable fact is the almost entire absence of the sub- 
family from the Australian Region, only two Philippine species of 
the Oriental genus Rhinocypha ranging into Papua. In Mada- 
gascar the group is represented only by one widely-ranging 
Hthiopian species (Phaon iridipennis, Burm.). And in the West 
