attached is very clear, but in other specimens the labellum 
appears to arise from the column just below the stigmas 
and to bear the lateral sepals on its base. As the presence 
or absence of a column-foot is structurally important for 
the recognition of sections in the Ornithocephaleae, I 
have emphasized this point. 
The genera of the Ornithocephaleae are prevalently 
Brazilian. Only Cryptarrhena, Ornithocephalus and Zy- 
gostates are known to occur in Middle America. From 
these genera Hintonella is markedly distinct. To find 
more closely allied genera it is necessary to bridge the 
great geographical gap between Mexico and Brazil. True, 
Sphyrastylis, at present known only from Antioquia in 
Colombia, and Dipteranthus, reported from Peru by Ru- 
dolf Schlechter, indicate the presence of allies in the 
intervening space. But these genera are also markedly 
different from Hintonella and emphasize the significance 
of geographical isolation. 
Hintonella Ames gen. nov. 
Divisio: Acrotonae. Tribus: Kerosphaereae. Subtri- 
bus: Ornithocephaleae. Perianthii partes liberae. Sepala 
subconniventia, extus per medium conspicue carinata. 
Petala sepalis similia, membranacea, Labellum leviter 
trilobum, cum columnae basi continuum, prope basim 
leviter saccatum. Discus per medium carinatus, medio 
lamina transversa membranacea ornatus, prope junction- 
em cum columna ecallo recurvato instructus. Columna 
prope medium constricta, exalata, in pedem producta; 
stigma infra medium columnae. Anthera subglobosa, im- 
perfecte bilocularis, in appendicem brevem_ producta. 
Pollinia quattuor, cerea, distincta, stipiti longiusculo 
membranaceo affixa. Ovarium hexalatum. Capsula glo- 
bosa, leviter alata. 
Herbae pusillae, epiphyticae, dense caespitosae, pseu- 
[ 186 | 
