670 FLORA OF SOUTH AMERICA. 
279. Polytrichum pallidisetum, is the common form of 
P. formosum. 
980. Polytrichum pallidisetum, var., is P. gracile Menz. 
284. Polytrichum urnigerum, is the var. B. crassum. 
BRUCH AND SCHIMPER. 
Contributions towards a FLora of SourvH AMERICA, 
Enumeration of Plants collected by Mr. SCHOMBURGK, 
in British Guiana.—By Georce Bentuam, Ese. 
(Continued from p. 378.) 
ORCHIDACES. 
(Determined and described by Dr. LINDLEY.) 
781. Pleurothallis emarginata, Lindl. Gen. et Sp. Orch. pe — 
6.—British Guiana, Schomburgk. 
782. Stelis ophioglossoides, Swartz.——Lindl. Gen. et Sp. 
Orch. p. 12.—Roraima Expedition, Schomburgk, n. 1025. 
783. S. argentata, Lindl. Bot. Heg. 1849. Misc. p. 64.— 
British Guiana, Schomburgk, n. 427. 
784. Bolbophyllum quadrisetwun, Lindl. (sp. n.), folio ob- 
longo-lanceolato acuto basi angustato, spica pedunculata — 
rectiuscula, pedunculo 2-3-vaginato equali, rachi tenui, brac- - 
teis ovatis floribus subzqualibus, sepalis acutissimis, petalis - 
linearibus acuminatis serrulatis, labello oblongo marginato 
bilamellato, columna biseta.— Flores coriacei resupinati. 
Petala et columnz sete subsimilia, Anthere callo cristate. 
British Guiana, Schomburgk. 
... 485. Epidendrum durum, Lindl. in Hook. Journ. Bot. 8 
— p. 87.— British Guiana, Schomburgk. 
786. E. rigidum, Jacg.— Lindl. Gen. et Sp. Orch. p. 110.— 
British Guiana, Schomburgk, n. 688. j 
787. E. clavatum, Lindl. Bot. Reg. t. 1870.—British Guiana, 
Schomburgk. 
788. E. longicolle, Lindl. Bot. Reg. 1838, Misc. p. 49.— : 
British Guiana, Schomburgk. 
789. E. viviparum, Lindl. Bot. Rey. 1840, Misc. p. 10.— 
British Guiana, Schomburgk. 
