CUAP. Vn. CATASETDM TEIDENTATUM. 193 



an almost white colour and formed of a thick mass 

 of succulent tissue, having a sweetish taste. Towards 

 the base of the labellum there is a large cavity, which 

 externally resembles the nectary of an ordinary flower, 

 but apparently never contains nectar. The pointed 

 extremity of the left-hand antenna lies within this 

 cavity, and would infallibly be touched by an insect 

 gnawing the bilobed and basal end of the medial pro- 

 jection of the labellum. The right-hand antenna is 

 turned inwards, with the extreme part bent at right 

 angles and pressed against the column ; therefore I 

 do not doubt that it is paralysed as in G. saccatwm; 

 but the flowers examined by me had lost almost all 

 their sensitiveness. 



Catasetum planiceps {?). — This species does not differ 

 much from the following one, so I will describe it 

 briefly. The green and spotted labellum stands on 

 the upper side of the flower ; it is jar-shaped, with 

 a small orifice. The two elongated and roughened 

 antennae lie coiled up some little way apart and 

 parallel to one another, within the labellum. They 

 are both sensitive to a touch. 



Catasetum tridentatum. — The general appearance 

 of this species, which is very different from that of 

 C. saceatum, caUosum and tabular e, is represented in 

 fig. 30, with a sepal on each side cut off. 



The flower stands with the labellum uppermost, that 

 is, in a reversed position compared with most Orchids. 

 The labellum is helmet-shaped, its distal portion being 

 reduced to three small points. It cannot hold nectar 

 from its position ; but the walls are thick, and have, as 

 in the other species, a pleasant nutritious taste. The 

 stigmatic chamber, though functionless as a stigma, 

 is of large size. The summit of the column, and the 

 spike-like anther, arc not so much elongated as in 



