CarprenteR—The Geographical Distribution of Dragonflies. 447 
sub-region ; and it is of interest to note that while one Pseudo- 
themis is closely allied to the tropical Rhyothemis, the other (The- 
cadiplax) is an offshoot of the northern Sympetrum. The other 
three peculiar Holarctic genera are Libelluda (European and 
Mediterranean sub-regions), Cenotiata (Huropean), and Leu- 
corhinia, which ranges over the Canadian, European, and Man- 
churian sub-regions, some species presumably awaiting discovery 
in the Siberian. It is important to note that this genus in 
America ranges south only as far as the northern States. 
Thirty-one genera of Libelluline are found in the EruioPian 
Reeton ; fourteen of these occur nowhere else, and three others 
only extend into the MascarenE Ruceion, which is comparatively 
very rich, having nineteen genera—one more than the great Hol- 
arctic Region. Of these nineteen, six are peculiar. It will be 
noted that the distinction of the Ethiopian and Mascarene Regions 
is well warranted, fourteen peculiar genera characterising the one 
region and six the other, while only three are peculiar to the two 
combined. Of the fourteen peculiar Ethiopian genera, twelve are 
confined to the West African sub-region. 
The Orienran Region is the home of forty-oue genera, nearly 
the same number as inhabit the Neotropical Region; only twelve of 
these are peculiar, but four others might be reckoned with them, as 
they only range into the adjoining Austro-Malayan district. 
Two genera (Athriamanta and Onychothemis) are Mascarene and 
Oriental only, the former occurring in Madagascar and India, the 
latter in Madagascar and the Philippines. 
The AustraLiAN Reeion has twenty-eight Libelluline genera, 
but twelve of these are wide-ranging or Oriental genera which 
only enter the Austro-Malayan sub-region. Hight of the Aus- 
tralian genera are peculiar. Only a single species of the wide- 
ranging Trithenis reaches New Zealand, but the Polynesian sub- 
region has representatives of eight genera; one of these (Hypo- 
themis) is peculiar to the Fijis. The Libellulines of the Sandwich 
Islands mostly show affinity with North American forms. It is 
interesting to note that as many as eleven genera are Oriental and 
Australian only. 
Turning now to the genera of wide range, we find that only 
eight are common to the tropical regions of both hemispheres. 
Tholymis is Oriental, Ethiopian and Neotropical (Antillean only). 
Pantaia has a wider range, being found all over the three regions 
just mentioned, and extends into the southern Sonoran and 
