casioned by the like swelling at the base of the lip: from the 
presence of this and the spur is derived the specific name 4i- 
gibbum. Petals large, nearly orbicular, horizontally patent. Lip 
deeper-coloured than the rest of the flower, three-lobed : /ateral 
lobes large, incurved ; middle lobe moderately reflexed, retuse at 
the apex: the disc has a large, elevated, white crest, papillose 
for the greater part of its length: the base is decurrent, and 
forms a gibbosity. Column large, compressed, grooved, the back 
closely united with the sepal, the clinandrium only standing a 
little forward. 
_ Fig, 1. Side view of the lip, and spur of the sepals. 2. Front view of the 
lip. 3. Column. 4. Pollen-masses. 
