124 DR. LINDLEY ON WEST AFRICAN TROPICAL ORCHIDS. 
the opportunity of examining and describing them, I am indebted 
to Sir William Hooker. 
Till the present time, the species of the Order known to exist 
in the region over which these collections have extended, were 
little known; the colony of Sierra Leone having supplied the 
greater proportion of the 19 previously described. Those now 
enumerated inhabit the middle and lower course of the Niger 
River, the country extending from Lagos to the Cameroons, with 
several from Fernando Po, where, however, Ansellia africana, the 
only species before known from that island, was not seen by 
Mr. Mann. In all, I have examined 67 species, of which 48 were | 
previously undescribed. 
Of those bearing a well-marked resemblance to other portions 
of the African Flora, the principal part resemble Cape species. 
These are Polystachya alpina, near P. Ottoniana ; Penthea Pumilio, 
a striking addition to a small Cape genus; Angrecum arcuatum, 
identical with the plant from Albany ; and Cymbidium adenoglossum, 
which resembles the C. tabulare of Table Mountain. 
Others must be compared with Eastern Africa: thus, Amphor- 
chis occidentalis is the second species of a genus inhabiting the 
Isles of France and Bourbon; Corymbis disticha is the same as 
the plant from the same islands; Calanthe corymbosa is very near 
C. sylvatica of the Isle of France; Habenaria prealta is undistin- 
guishable from the Bourbon species; and Bolbophyllum lupulinum 
has all the appearance of B. occultum from the Mauritius and 
Bourbon, although the structure of the flowers is widely different ; 
finally, there is a new Notiophrys, near N. occulta, from the same 
islands. To these special resemblances must be added the generic 
similarity among many species of Bolbophyllum, Polystachya, and 
Angrecum, in Eastern and Western Africa: the collections con- 
taining 14 species of the first, the same number of the third, and 
9 of the second. 
Perhaps the most striking geographical fact consists in the pre- 
sence of the Asiatic Epipogum nutans at Ambas Bay, a place a 
little to the north of the embouchure of the Cameroons River. 
It is worthy of remark in conclusion that there is little resem- 
blance between the species now described and those of Abyssinia ; 
there is no Satyrium, no Peristylus, no Pterygodium ; and the 
species of Habenaria are quite dissimilar. It is only in the case 
of Eulophia guineensis, the Saccolabium abyssinicum of Achille 
Richard, that the identity of a West African and Abyssinian plant 
has been ascertained. 
