tiicliijo)i is the type of Dr. Hooker's genus Polystacliya ; 
D. utriculariok/es, and probably te^ticu latum, jire species ol" 
lonopsis; D. palmifolitm vina Sarringtonia belong to the 
oeiiiis now reformed. Of llic few remaining- after these 
deductions, the East Indian kinds are probably genuine 
species of Dendrobium, and most of the others require 
further examination. 
The genus Dendrobium, as limited by Mr. Brown in the 
2d editi(m of the Hortus Kewensis, should include no species 
except those with 4, parallel, distinct pollen-masses ; and 
will consequently contain only the East Indian species, 
which form a numerous group, distinctly characterised by 
the character above mentioned, and naturally connected 
by liabit. They are trailing or erect parasites, without 
bulbs, but with long, leafy, or naked round stems, producing 
t^je flowers from their axillae, either singly, or in few- 
flowered fascicles. From these, the American species, 
agreeing with them in general structure of perianthium, 
-are now divided. They are distinguished by having only 
two pollen-masses, each divided down the mdidle, and 
connected at the base by a common, glandular process ; and 
by being all bulbous. Besides the kind now published, 
D. Barringtoniae {Maanllaria Barringtonia Nob.) and 
D. palmifolium (71/. palm/folia Nob.), belong to the genus 
Maxillaria, which will be increased by the examination of 
the numerous Dendrobium-like plants of the continent of 
South America. It is distinguished from Polystachya by 
the structure of its perianthium, and by its radical in- 
florescence. 
Neai ly related to Maxillaria, in general characters, and 
in geogra[)hical position, is a genus of which the plant 
published at tab. 732 of this work, under the name of 
Dendrobium squalens, must be considered the type. This 
plant has only two pollen masses, furrowed on each side, 
and its flowers are in their natural position. It may be 
called Xylobium, and thus characterised : 
XYLOBIUM. 
Perianthium rectum, patens. Labellum cum processu unaniformi ro- 
lumnaj articulatum, trilobuni. in columna incumbens. Sepald lateralia 
exteriora basibus ( lun processu columnae connata. PoUiiiia 2, hinc sulcata. 
Herba? hahitu Muxilhirw. 
Sp. 1. Xylobium squalens. 
Dendtobmoi iqualens. Suprd t. 733. 
