ORCHIDACE^ 



with a minute lobe that is approximately .5 mm. wide and sit- 

 uated on the posterior margin. Labellum 7 mm. long, about 4 

 mm. wide at the broadest part (2.5 mm. above the base), sub- 

 hastate in outline from a cuneate claw, three-nerved, near the 

 base on each side provided with a falcate, obtuse lobe that is 

 about 3 mm. long and shortly decurrent along the lateral nerve, 

 slightly angled on the exterior margin and cucuUate at the tip. 

 Between the lateral lobes, on the disc, there is a small oblong 

 callus which is truncate at both ends. Below the middle of the 

 lip, on either side, there is apparent in dried specimens a thick- 

 ening of the surface tissues of the disc. Column with broad wings, 

 minutely three-lobed at the apex behind the anther, the middle 

 lobe minutely denticulate. (Plate 114.) 



British Guiana, Potaro, ten miles south of Potaro Landing, lat. 5° 10' 

 N., long. 59° W., J. S. Hitchcock i7^P^, January 7-8, 1920. Distributed by 

 the United States Department of Agriculture, Gray Herbarium of Harvard 

 University and the New York Botanical Garden. 



Pleurothallis Schaferi v47?^e5 sp. nov. Aff. P. elegantulaeet 

 P, rhomboglossae Lindl. Planta inconspicua, caespitosa, vix 1 

 cm. alta. Radices carnosae, glabrae. Caules secundarii abbrevi- 

 ati, inconspicui, plus minusve 2 mm. longi, monophylli. Folia 

 cum petiolo 4-6 mm. longa, usque ad 3 mm. lata, coriacea, el- 

 liptico-oblonga, marginata, margine scabridiuscula, apice retuso- 

 apiculata, in petiolum plus minusve 1.5 mm. longum sensim 

 attenuata. Scapus gracilis, usque ad 8 mm. longus, glaber, infra 

 racemum paucibracteatus, vulgo bibracteatus. Racemus pauci- 

 florus, vulgo triflorus, vix 3 mm. longus. Bracteae inflorescentiae 

 subinfimdibuliformes, 1 mm. longae, scariosae. Pedicellus cum 

 ovario 1 mm. longus, leviter arcuatus, glaber. Flores minuti, in 

 sicco albidi et semipellucidi, plus minusve 2 mm. longi. Sepala 

 lateraHa 1.75 mm. longa, plus minusve 1 mm. lata, anguste Ian- 



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