700 ORCHIDES. 



ONCIDIUM. 



For the distinction betvveen this well-knowu genus and Odontoglos- 

 suni, Ihe reader is referred to Ihat article. 



In some of the sections, whether arlificial or natural, into which On- 

 cidium is here divided, the limils of the species are clearly definable ; 

 in olhers it is extremely doubtful, whether some, which the author still 

 retains ought to be aduiitted as anythinir more than lorras of one com- 

 mon type, as for example, among the Phirituberculala. It vvill also be 

 found, thal supposed species are absolulely reduced wilhout hesitation 

 to an extenl , which the author once thoiight improbable; bul many 

 months* very careful crilical re-examination of all the copious materials 

 at his command leaves no doubtupon his mind, that at least Ihose sup- 

 posed species, which are novv cancelled oughl never to have been ele- 

 vated to that rank ; he must, however, add, that the badness of mate- 

 rials, Ihe imperfection of drawings and descriplions, and Ihe misinfor- 

 mation so common in gardens concerning counlries, have rendered such 

 errors unavoidable, even if no account is talfen of the haste with which 

 a botanist working wilhout leisure must necessarily act. 



He would add, that in the revision of this genus his thanks are not 

 only due to his usual correspondents, but most especially to Professor 

 11. G. Reichenbach jun. of Leipsig, a most acute and experienced orchi- 

 dologist, wilhout whose invaluable assistance it would have been impos- 

 sible to form an opinion concerning many species published by conti- 

 nental writers; he has also to acknowledge his special obligations to 

 the Adminislration of the Museum of Natural History, Paris; to Messrs. 

 Linden and Galeotti ; to Mr. Miers ; and to Sir W. J. Hooker; all whose 

 materials have been placed in his hands without reserve. 



Analysis of the sections. 



Labellum nanum coriaceum (Cyrtoctiilum H. B. K.) §. 1. Microchila. 1—125. 

 Labellum dilataium membranaceum. Clinandrium 

 margiue nudum. 



Folia equitantia S- 2. Equitantia. 26—38. 



., tereiia §.3. Tcretifolia. 39—43. 



,. plana. 



Sepala laieralia coniiata Telrapetala. 



Labellum margine barbalum S- ^- ^arbata. 44—49. 



,) „ laeve. 



Petala mulio majora .S- ^- Macropetala. 50—64. 



subaequalia S- ^- Miaopelala. 65—82. 



Sepala lateralia libera Pentapetala. 



Pelala mulio niajora S- ^- Macropelala. 83—99. 



Petala subaequalia. 

 Labellum indivisum t. apice tantum lobatum i 

 V. basi ulrinque unidenlatum j S- 8. Integrilabia. 100-116. 



Labellum auriculatum panduratum basi an- 

 gtistius, V. lobo terminali aequali. 



crista pulvinaia s. villosa S- 9- Pulvinata. 117—120. 



,, tuberculata. 

 luberculis 2—4 ■ . S- 10. PauciluberctUala. 121—125. 



