ORCHIDACE. 
Tribe V. ARETHUSEZ. 
OrcHIDE Æ, Tribus ARETHUsEx, et GASTRODIEÆ. Lindl. Orch. Scel. 7 and 10. Va- 
NILLACEZ. Id. Key to Botany 73. Nat. Syst. ed. 2. 341. 
Pollen pulvereum, aut in lobulos minutos elasticè coherentes colligatum. 
Anthera terminalis, opercularis, persistens aut decidua. Herbae habitu 
Varia sæpius terrestres, rarius epiphyte, regiones temperatas utriusque 
hemisphere, presertim australis, habitantes, in Africà verosimiliter 
ignote; quzdam aphylle, in radices plantarum parasitice, rufe, 
Orobanchis facie. Folia membranacea, graminea, nunc reticulata, nunc 
plicata, aliquando succulenta, rard dura evaginata et cum caule complet 
articulata. Flores plurimarum membranacei, speciosi, rarius parvi et 
herbacei, 
After much consideration, and a careful examination of a large pro- 
portion of the species hereafter described, I have come to the conclu- 
sion that Gastrodiez, a section first limited by Dr. Robert Brown, are 
not to be considered of the same importance as the other tribes ad- 
mitted in this book, but as a mere section of Arethusee. In like man- 
ner my Vanillacee lose their distinctive character through Cyrtosia of 
Blume, which, till it was published in the Rumphia with a figure, I 
had supposed to be a genus of Malaxidee. 
Confined within the limits now proposed, Arethusee form a distinctly 
marked tribe of Orchidacez, passing into Ophrydee through Gastrodiex, 
and especially the genus Ceratopsis, and into Neottiee by Microtis. The 
&enus Cyrtostylis may be considered an analogue of Liparis among Malaxi- 
dez, and Limodorum of Orchis in Ophrydee. Sobralia and Cyathoglottis 
represent the Evelyna of Epidendrex ; but I find nothing that can be 
Compared with any known genus of Vandeæ, taking both flowers and 
leaves together. The nearest approach is apparently through Geodorum 
to Cephalanthera. 
ARTIFICIAL ANALYSIS OF THE GENERA. 
Div. ]. GasrTnRopiEX. Pollen sectile : lobulis elasticé coherentibus. Stigma 
ad columna basin. 
- 215. GasTRODIA. 
Perianthium monophyllum. z " 
214. GAMOPLEXiIS. 
Perianthium pentaphyllum. 
Labellum indivisum, calcaratum. e - 213. CERATOPSIS, 
s 212. EPIPOGIUM. 
Labellum trilobum, saccatum. - 
January, 1840. DDD 
