MB. G. BENTHAM ON OECHIB-EjE. 329 



originally in Oncidivm, but with a rostellum approaching that of 

 Zygostates, and the habit nearly of Ionopsis, without pseudobulbs 

 in the specimens I have seen ; but, according to Kunth, the upper 

 leaf-sheath thickens into a pseudobulb, as in the rest of the present 

 series. 



Gomesa, E. Br., six species," confounded by Lindley, as above 

 mentioned, with JRodriguezia, Ruiz & Pav., has been united by 

 Eeichenbach with Odontoglossum, and Abola, Lindl., a single 

 species, with his Mesospinidium ; but both appear to me to be 

 sufficiently characterized to be retained as substantive genera. 

 Neodryas, Eeichb. f., three species, differs very little from Onci- 

 dium, except in the rather less spreading perianth. Trizeuxis, 

 Lindl., Ada, Lindl., and Sutrina, Lindl., are all three monotypic, 

 but well established. Eeichenbach in uniting Ada with his 

 Mesospinidium, distinguishes two species, Lindley's Brassia 

 cinnabarina and Ada aurantiaca ; but after a careful comparison 

 of the specimens the two appear to me to be quite identical. 

 Trigonidium, Lindl., is a natural genus of seven or eight species, 

 strongly characterized by the union or connivence of the sepals 

 in a triangular tube. 



Series 5. Labellum liberum, ecalcaratum. Caulis foliatus brevis, 

 ebulbosus. — Eight genera, all distinct and well established : — 

 Ionopsis, H. B. & K. (lanthe, Hook., Cybelion, Spreng.), ten pub- 

 lished species, but several of them varieties of /. pulcJtella ; 

 Cryptarrhena, E. Br. (Orcliidofunkia, A. Eich.), two species; 

 OrnitJiocepJialus, Hook., about eight species ; Quekettia, Lindl., 

 a single one ; Zygostates, Lindl. (Dactylostyles, Scheidw.), three or 

 four species ; JBliymatidium, Lindl., two species ; Chytroglossa, 

 Eeichb. f, two species ; and Hqfmeisterella, Eeichb. f ., a single 

 one. 



Cohnia and Papperitzia, Eeichb. f., genera founded on single 

 herbarium specimens, are both unknown to me, and the characters 

 given are not sufficient to judge of their affinities beyond re- 

 ferring them to the subtribe Oncidiese. 



Subtribe 7. Saecanthe-E. — The chief character of this sub- 

 tribe is vegetative. The genera are all epiphytical and never 

 pseudobulbous. The stem or caudex, corresponding to the 

 rhizome of the preceding subtribes, creeps and bears adventitious 

 roots at least at the base, and often for its whole length. It is 

 usually clothed with scarious or closely appressed leaf-sheaths ; 

 the leaves themselves are more or less distichous, fleshy, or 



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