MB. G. BENTHAM ON OBCHIDEjE. 353 



apparently conspecific with the Japanese Aceras longicruris, C. 

 Wright. Aopla, Lindl., is the Herminium reniforme, Wall., with 

 a floral structure almost the same as that of H. grandijlorum, 

 Lindl. Stenoglottis, Lindl., is a single South-African species dif- 

 fering but little from Herminium, but with a character requiring 

 some slight modification from that given by Lindley. Arnottia, 

 A. Rich., has two Mascarene species with the habit of Gynorchis, 

 but with the floral structure nearer that of Herminium and Ste- 

 noglottis. 



Bartholina, E. Br., is a siugle South-African species, distin- 

 guished as well by its uuifoliate uniflorous stem as by its singular 

 labellum and anther. Huttoncea, Harv., and HallacJiia, Harv., 

 are two South-African plants, evidently congeners, and readily 

 known by the very exceptional form of their petals. Holothrix, 

 Lindl., should, I think, include the same author's genera Sacci- 

 dium, Monotris, Bucculina, Scopularia, and Tryphia ; we should 

 then have a very natural small-flowered genus with a peculiar 

 habit, and characterized by the narrow petals and labellum all 

 longer than the sepals. There are about eighteen species known, 

 all African, two of them (as yet unpublished) Abyssinian, the 

 others all southern. Bicomella, Lindl., contains two Mascarene 

 species scarcely distinguished from Habenaria by two appendages 

 starting from the base of the labellum and adnate to the sides of 

 rostellum. Habenaria, Willd., is now a vast cosmopolitan, and 

 in many respects polymorphous, genus, of which there are about 

 350 species in the Kew berbarium, and perhaps 50 more, already 

 published, are not there represented. The differences observed in 

 the anther-cells, in the stigma, and in various appendages to parts 

 of the flower are so great, that numerous attempts have been made 

 to dismember it ; but the single characters assigned have all proved 

 either so variable from species to species, or so little in accord- 

 ance with any other distinction, that I feel compelled to re- 

 unite the proposed genera after the example of A. Gray and some 

 other recent botanists, although I cannot go so far as to agree 

 with Grrenierand Grodron in uniting the whole genus with Orchis. 

 As it is, I have had to record no less than twenty-eight generic syno- 

 nyms ; and in proposing to distribute the species into the follow- 

 ing ten sections I cannot but feel considerable doubts as to the 

 definiteness of the characters assigned to some of them, these 

 characters being often very difficult to ascertain in dried speci- 

 mens, the only ones I have had to work upon. 1. Gymnadenia, 



