148 ORIGIN, ETC., OF THE FLORA. 
restricted sense of Bentham and Hooker, four-fifths are common to both Hemispheres. 
The families confined to America are twenty-five in number, namely, Batidacee, 
Bromeliacez, Calyceraceee, Cannacez (Scitaminee *), Caryocaraceze (Ternstreemiacee), 
Columelliacee, Cyclanthacee, Cyrillacee, Fouquieracee (Tamariscine), Gomortegacee, 
Lacistemacee, Leitneriacee, Lennoaceee, Limnanthacee (Geraniacee), Malesherbiacee, 
Marcgraviacee (Ternstroemiaceze), Martyniacee (Pedalinee), Myzodendracee, Qui- 
inacee, Sarraceniacee, Thurniaceee, Tovariacee (Capparidaceze), and -'Tropzolacez 
(Geraniacee). 
The foregoing families are of various categories. Eleven of these are limited 
to a single genus each, and the Bromeliacee is the only one exhibiting a considerable 
development of genera and species, now numbering forty-five and about a thousand 
respectively, generally dispersed in tropical and south temperate America. Twelve 
out of these twenty-five families are not known to be represented within the limits 
of the ‘ Biologia.’ 
Fourteen families are peculiar to the African region (including Madagascar and the 
Mascarene Islands), so far as known, eight of which are monogeneric. The only one 
of considerable development is the herbaceous Selaginacez, associated with the 
Scrophulariaceee by Engler. The Chlenacee, comprising six genera and about 
twenty-five species, are peculiar to Madagascar. ‘They belong to the Malvales, and 
are shrubs and small trees with showy flowers. 
A group of small and interesting families inhabiting eastern Asia, consisting of the 
Cercidiphyllacee, Kucommiaceer, Pentaphylacacee, Stachyuracee, and Trochodendracee,. 
of remarkable affinities, is not represented in North America, but Engler places 
Pentaphylax near the American Cyrillacez. 
In spite of its highly differentiated vegetation, the Australian flora counts few 
peculiar families; indeed, the only ones absolutely limited to Australia are the 
Cephalotacew, restricted to the singular Cephalotus follicularis, the Eupomatiacee 
and the Tremandracee, allied to the Pittosporacew, which, except the widely spread 
genus Pittosporum, are all Australian. But there are some characteristic Australasian 
(including New Zealand, New Caledonia, etc.) families with a few solitary outliers— 
such are the Centrolepidacee, represented by one species in China and one or two 
species in the extreme south of America, and the Epacridace, with a few outliers in 
Malesia and Polynesia, and the monotypic Lebetanthus in Fuegia. The Eucryphiacee 
(Eucryphia), limited to about four species in Australasia and Chili, and the somewhat 
numerous and generally dispersed Australian Stylidiacee are represented outside of 
Australasia by solitary outliers only in India, Malaya, and Fuegia. 
In addition to the above-named families, there are some twenty-five others peculiar 
to the Old World (with some extensions in Polynesia), but inhabiting two or more of 
* The family-name under which the groups in question appear in the “ Botany ” of the ‘ Biologia.”—W.B.H, - 
