SACCOLABIUM LONGIFOIJtTM, &C. 83 



The only marked difference in colour is on the area surround- 

 ing the disc. In S. longifolium the disc is bordered by a broad, 

 vivid purple -red zone, and the horns at either corner of the 

 column are red. In S. Wightianum there is a narrow red zone 

 at the base of the column, but the edge of the disc is j^ellow, 

 and the horns at the top of the column are also yellow. 



The outstanding difference between the two flowers lies in 

 the upper surface of the lip. In *S. Wightianum this is tuber- 

 culate, but in S. longifolium it is tomentose. 



The distinguishing differences between the two species, as 

 known in Ceylon, are, therefore, the relative lengths of the 

 inflorescence and the structure of the lip. 



S. longifolitim, has an odour resembling that of the Lily of 

 the Valley. 



