Pleurothalhs diffusiflora seems to be allied to P. hians 
Lindl., but the flowers are smooth inside with an un- 
guiculate very different lip. 
Bririsn Guiana, Essequibo River, Moraballi Creek, near Bartica. 
Nearly at sea-level. ‘“‘Epiphyte, in Wallaba forest. Sep. greenish- 
yellowish-mauve, mottled with chocolate. Upper pet. and labellum 
dark chocolate.’’ October 7, 1929. N. Y.Sandwith 474 (Tyee in Herb. 
Kew.) ; Barama Falls, ““5 x 1. 96.7? E. F. im Thurn 172 (Herb. 
Kew.) : im Thurn 116 (Herb. Kew.): Near No. 6 Camp, Barima- 
Barama Road. ‘‘Sepals pale yellow green with distinct scattered spots 
of deep rich purple; petals the color of sepals but purple spots more 
numerous especially at the upper edges which are quite covered by the 
deeper color; lip with an almost bulbous swelling at apex which is 
light bright purple, otherwise yellow green with closely set small dark 
purple spots along edge and a large patch of deep purple at foot of 
column.” February 1897. im Thurn 178 (Herb. Kew.) 
Pleurothallis minima (. Schweinfurth sp. nov. 
Herba minima, caespitosa. Radices fibrosae, crassae, 
Caules brevissimi, unifoliati. Folium cuneato-spathula- 
tum vel spathulato-ellipticum, marginatum. Inflorescen- 
tia singula, filiformis, pauciflora, Sepala lateralia in lami- 
nam rotundato-ellipticam bidentatam connata. Sepalum 
dorsale lanceolatum. Petala elliptico-lanceolata, falcata, 
fimbriata. Iabellum simplex, oblongum, apice rotunda- 
tum, margine longe ciliatum. 
Plant minute, caespitose. Roots fibrous, glabrous, 
stout for the plant. Stems very short, about 1.5 mm. 
long, unifoliate, 1-jointed, entirely concealed by a tubular 
membranaceous evanescent sheath. Leaf cuneate-spatu- 
late to spatulate-elliptic, up to 7 mm. long and 8 mm. 
wide, acute to rounded at the apex, cuneate-narrowed 
at base, marginate. Inflorescence solitary, filiform, sub- 
equaling or exceeding the leat, up to 5-flowered. Flowers 
membranaceous, large tor the plant. Lateral sepals con- 
nate to above the middle forming a round-elliptic sharply 
[ 82 | 
