similar. Petals 1 mm. long, 1.5 mm. wide, flabelliform, 
thickened at the broad apex along the margin, 1-nerved. 
Labellum 1 mm. long, 1 mm. wide, constricted below 
the middle, cordate, obtuse at the apex, with a pulvinate 
glandular-papillose callus below the middle. Column 
equalling the petals, lightly 8-lobed at the tip or almost 
entire, stigmas confluent on the anterior surface near the 
summit beneath the triangular rostellum. Pollinia two. 
In the broad petals and in the structure of the col- 
umn. Stelis latipetala is closely allied to S.erescentiicola 
Schitr. but is much larger in all of its parts. 
If the labellum is viewed directly from above, two 
rounded calli are discovered, one on each side of the disc, 
with their apices retrorse or convergent and almost con- 
tiguous. These calli are coalescent with the glandulose 
basal callus from which they are clearly differentiated by 
their deeper color. The basal callus becomes abruptly 
narrowed at its distal end and fills the space between the 
lateral calli forming with them a more or less well-defined 
transverse septum. This remarkable peculiarity charac- 
terizes several other species of the genus, but is by no 
means prevalent. That it is associated with the phenome- 
na of pollination by insects seems highly probable. When 
this peculiarity is represented ina drawing there appears 
to be a circular hole at the centre of the dise, almost 
closed at the top. This is well shown in figure 4. 
Costa Rica, Cachi. Flowers maroon, seventy or more in each 
raceme. September, 1925. C.H. Lankester 1101 (‘Tyrer in Herb. Ames 
No. 31109). 
Stelis Storkit Ames sp. nov. 
Radices fibratae, albidae, glabrae. Caules secundarii 
dense caespitosi,vaginis amplis obtecti,monophylli. Folia 
oblanceolata, bene marginata, coriacea, apice breviter 
apiculata, infra medium in petiolum suleatum gracilem 
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