486 Annals of the Carnegie Museum. 



Roots fasciculate; spike 2-7 cm. long. 



/. gracilis (I5igelo\v) House. 

 Carnegie Museum, 

 January 15, 1906. 



Exri.ANAriox of Plate XX. 



A. IbiiliiiDi i>u-iii7'itm. Whole plant. One half natural size. 



y>. Floral bract. Twice natural size. 



O. Ovary. Twice natural size. 



C. Column. Twice natural size. 



S. Sepals. Twice natural size. 



P. Lateral petals. Twice natural size. 



P' . Lip, >i. Callosities. Twice natural size. 



