bidentate lamina which is about 2 mm. long and sub- 
equally broad, 2- or less distinctly 4-nerved. Dorsal sepal 
lanceolate, nearly 2.7 mm. long, about 1 mm. wide, acute, 
concave, indistinctly 8-nerved. Petals elliptic-lanceolate, 
faleate, about 1.9 mm. long and 0.9 mm. wide, acumi- 
nate, more or less obtuse, fimbriate on the margins except 
near the base, 1-nerved. Lip simple, oblong with strongly 
revolute margins, when expanded about 2 mm. long and 
0.6 mm. broad, rounded at the apex, minutely unguicu- 
late with parallel auricles at base, convex but longitudi- 
nally sulcate through the middle of the lower half, pro- 
vided with fine cellular hairs on the margin especially near 
the apex. Column strongly arcuate, about 1.2 mm. long, 
with a coneave membranaceous wing which is dilated 
tridentate and denticulate at the apex, extended into a 
short foot. 
Pleurothallis minima is allied to P.barbulata Lindl., 
but differs in having fimbriate petals and a scape which 
commonly surpasses the leaf. [t differs from P. ciliolata 
Schltr. in its smaller flowers and dissimilar lip. 
Bririsn Guiana, B.-B. [ Barima-Barama] Road. “'25. VIII 96."’ 
E. F. im Thurn 166 (Tyrer in Herb. Kew.) 
Pleurothallis pertenuis C.Schweinfurth sp. nov. 
Herba nana, tenuissima, caespitosa. Caules brevis- 
simi, unifoliati. Folium lineare vel oblanceolato-lineare. 
Scapus uni- vel biflorus, tenuis, folium subaequans vel 
superans. Sepala lateralia in laminam usque ad medium 
bidentatam elliptico-ovatam connata. Sepalum dorsale 
lanceolatum. Petala anguste oblongo-spathulata, valde 
obliqua, abrupte acuta. Labellum sagittato-oblongum 
cum angulis triangularibus infra medium, apice rotun- 
datum. 
Plant dwarf, very slender, caespitose. Roots fibrous, 
glabrous, numerous. Stems very short, monophyllous, 
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