to 8.4cem. long and 4.5 mm. wide, the mid-nerve promi- 
nent beneath. Inflorescences axillary, fascicled, one or two 
flowers appearing at a time. Flower membranaceous. 
Sepals 8-nerved. Lateral sepals free, lanceolate to ovate- 
lanceolate, 3.5-4.5 mm. long, 1.2—2 mm. wide, obtuse 
acute or acuminate, somewhat asymmetric. Dorsal sepal 
very similar, concave. Petals lanceolate or ovate-lanceo- 
late, about 3-3.5 mm. long, 1—-1.5 mm. wide, acuminate, 
1-nerved with a short supplementary nerve on each side 
at the base, more or less asymmetric. Lip ovate-elliptic 
in outline, 3-lobed near the middle, about 2 mm. long 
and 1.8 mm. wide across the lateral lobes; lateral lobes 
small, rounded-auriculiform; middle lobe much larger, 
ovate, acute, erose-dentate or denticulate near the apex ; 
dise 8-nerved, bicarinate with the keels extending from 
the middle of the lateral lobes almost to the middle of 
the mid-lobe. Column arcuate-cylindric, dilated at the 
base, about 1.4 mm. long on the posterior surface, ex- 
tended into a prominent foot. Pollinia complanate-pyri- 
form. 
The specimen from Arakaka (mm Thurn s.n.) shows 
twostems about 5—5.5 em. high of which one is distinctly 
4-jointed. The column of the single flower present is 
about 1.1 mm. long, measured on the dorsal surface. 
Octomeria parvula is vegetatively similar to O.par- 
vifolia Rolfe, but differs markedly in flower structure. 
Britisu Guiana, Essequibo River, Moraballi Creek, near Bartica. 
Nearly at sea-level. “‘Epiphyte. Fl. wholly lemon-yellow (including 
stele and labellum).’’ September 11, 1929. N. Y.Sandwith 234a (Typr 
in Herb. Kew.): Arakaka. February 1896. E.F. im Thurn s.n. (Herb. 
Kew. on sheet with Octomeria integrilabia C.Schweint. ) 
[91 ] 
