JuLy, 1912.] THE ORCHID REVIEW. , 205 
or paniculate, but occasionally solitary on the peduncles. Bentham included 
thirty-two genera in the Sarcanthex, but Lockhartia, Centropetalum, and 
Pachyphyllum are now excluded, while a few have since been described, and 
it is estimated that the group now contains about forty genera and upwards 
of 500 species. The majority of the genera are Indo-Malayan, a few 
reaching Australia, but Angrecum, Listrostachys, Mystacidium, AZonia, 
Cryptopus, and Aéranthes, are African and Mascarene, while Dendrophylax 
and Cryptocentrum are tropical American. 
Although the group, as a whole, is very well-defined, it is difficult to 
subdivide naturally, and much difference of opinion exists as to the limits 
of some of the genera, owing to the diversity of floral structure. Bentham 
subdivided the group into three series, founded on the presence or absence 
of a mentum to the perianth or of a spur to the lip, though he pointed out 
that the distinction was not always well marked. 
In the group having neither a foot to the column nor a spur to the lip 
Bentham placed the four following genera: Luisia, ranging from North 
India and Japan to New Caledonia, and having about 15 species, with terete 
leaves, and quaintly-shaped flowers; Cottonia, now limited to the South 
Indian C. macrostachya, Wight, with a paniculate inflorescence and a beetle- 
shaped lip; Stauropsis, ranging from India and China to New Guinea, and 
now including about twelve species, with rather fleshy flowers, arranged in 
spikes or panicles; and Arachnanthe, an Indo-Malayan genus of about ten 
species, in which the lip is articulated to the base of the column. It 
contains the remarkable Arachnanthe Lowii, which bears two differently- 
coloured kinds of flowers, the object of which still remains a mystery. 
Esmeralda, Rchb. f., based on Vanda Cathcartii, Lindl., was included 
in Arachnanthe by Bentham, and the two agree in having an articulated 
lip. Diploprora, Hook. f., has since been separated from Cottonia on 
account of its different habit and structure. It contains a single species, 
ranging from India and South China to Ceylon. : 
Bentham’s next group was characterised by having a short foot to the 
column, to which the sepals are adnate at the base, and the lip either 
spurless or with a spur remote from the base. Seven genera were included ; 
Phalznopsis, with about forty species, mostly Malayan; Doritis, with about 
six species, natives of India and Malaya; Rhynchostylis, with two or 
three species, of similar distribution ; Sarcochilus, with over 100 species, 
and ranging from North India to Australia and the Pacific Islands; 
Trichoglottis, now including about twenty Malayan species; Aérides, with 
about forty species, ranging from North India and Japan to New Guinea; 
and Aéranthes, an interesting Mascarene genus now containing about eight 
species. Sarcochilus was extended to include several other genera which 
had been recognised by Lindley, Blume and others, and which, it ‘is 
