intermediate between the smallest and medium-sized 
flowers and may be considered as typical of M. histrio). 
The largest flowers on the raceme are rigidly coriaceous 
and might well be taken for those of an entirely different 
species. The lateral lobes of the lip (fig. 2) are rigidly 
divaricate and scarcely or not at all twisted but merely 
slightly rolled up at the apex. This same collection also 
has racemes composed of flowers of only one type, either 
the largest or the smallest. A collection from Guatemala 
(Standley 259) also shows similar evidences of floral 
polymorphism but has only large and small flowers on 
the same raceme. 
1. Mormodes lineatum, lip, when flattened, two and 
one half times natural size. 2 and 3, Mormodes his- 
trio, two types of lip taken from the same raceme, 
natural position, two and one half times natural size. 
Drawn May 1941 by G. W. Ditton 
[17 ] 
