inflorescence of P. lancilabris is extremely lax, whereas 
that of P. Halbingeriana is very congested. The habit 
of P. Halbingeriana is much more obviously repent than 
that of either P. propinqua or P. lancilabris. 
Pleurothallis Halbingeriana is a very small inconspic- 
uous epiphyte growing deeply imbedded in moss on 
coffee trees in a partly cleared forest near the town of 
San Juan Lalana in the District of Choapam. The type 
of this orchid was found on a large coffee tree growing 
beneath a robust T'alauma mexicana (DC.) Don (eaca- 
lovochitl) on the forest trail which leads southeast from 
the town. I did not find Pleurothallis Halbingeriana on 
any tree other than Coffea arabica L., although almost 
all the trees in the vicinity supported epiphytic orchids, 
ferns and mosses. It occurred in the type locality in asso- 
ciation with Oneidium pumilum Lind). 
The flowers of Pleurothallis Halbingeriana are pale 
yellowish green in all their parts and are not easily no- 
ticed, although in May the little plant flowers in great 
profusion. ‘The Chinantec Indians of San Juan Lalana 
refer to this species, and to other small epiphytic orchids, 
as dzu. 
Pleurothallis lancilabris ( Reichb.f. ) Schlechter in 
Fedde Repert. 12 (19138) 205. 
Mexico: Oaxaca, District of Cuicatlin, Cerro Machin, San Juan 
Zautla, long. 96°40’, lat. 17°58’, altitude 450 m., June 29, 1939, 
Schultes 738. 
Hitherto, Pleurothallis lancilabris has been considered 
endemic to Costa Rica where it is very abundant. The 
extension of the range of this orchid to the northeastern 
part of Oaxaca is very significant because it indicates the 
possibility that subsequent work may extend to southern 
Mexico a complex of species which is not represented in 
herbaria by Mexican collections. It is one of the closest 
allies of Pleurothallis Halbingeriana of Oaxaca. 
[ 35 | 
