Explanation of PL XII. 



Dendrobium erythroylossum HAYATA. 



Fig. 1. The plant. 



2. A dorsal sepal. 



3. A lateral sepal. 



4. A ''petal. 



5. A labell um. 



6. Margin of the labellmn. 



7. Column. 



8. Apical portion of the same, seen from back. 



9. Operculum, seen from side. 



10. The same, seen from back. 



11. Pollinia. 



