lamina which is broadly ovate, about 8.2 mm. long and 
4.7 mm. wide, concave below, 6-nerved, bicarinate dor- 
sally. Petals parallel to and surrounding the lip in natu- 
ral position, slightly exceeding the lip, narrowly linear, 
slightly faleate below, about 7.5 mm. long and 0.9 mm. 
wide, acute, I1-nerved, minutely crenulate below. Lip 
very shortly and broadly unguiculate; lamina ovate-ob- 
long, cordate at base, very thickly fleshy, slightly re- 
curved and longitudinally sulcate in natural position, 
about 5.2 mm. long from a basal auricle to the tip, 2.7 
mim. wide across the dilated base, with a minute incurved 
apicule at the tip, above the middle minutely crenulate 
on the margins. Column short, very stout, characteristic 
of the allied group of species. 
Another collection, #’. Matuda S-200, differs from the 
type in having shorter stems, smaller more ovate leaves 
(as small as 6.6 cm. long) and smaller flowers. 
Pleurothalis Matudiana is vegetatively similar to 
many species of the alliance of P.cardiothallis Reichb. f. 
In particular, it differs from the Costa Rican P. phyllo- 
cardia Reichb.f. in having only a small and inconspicu- 
ous spathe surrounding the flowers and in having very 
narrow petals and lip. 
Mexico, State of Chiapas, Siltepec. August 8, 1937. bh. Matuda 
1577 (Type in Herb. Ames No. 46687) ; State of Chiapas, Mt. Pas- 
itar. August 3-4, 1937. F.Matuda S-200. 
[ 103 | 
