320 MH. H. N. RIDLEY’S REVISION OF THE 
angulum angustum ; sepala lateralia connata varie fissa binervia ; 
petala a latiore basi lineari-ligulata uninervia; labellum sagit- 
tatum oblongum triangulum, linea callosa marginante ante 
apicem incurrente. 
Huatusco, Richard. Costa Rica, Voleano de Barba, Wendland. 
I do not know this species, which seems to be closely allied to 
M. maianthemifolia, but differing in the shape of its leaf, which 
is ovate and acute in the latter. The value of the eonnation of 
the two lateral sepals I am not certain of; it is apparently irre- 
gular in amount in this species, and I expect is really abnormal. 
5. MICROSTYLIS ARACHNIFERA, n. Sp. 
Caulis 3-uncialis, gracilis, basi vix incrassata; folium singulum 
suberectum basi amplectens lanceolatum obtusum, 2 uncias lon- 
gum, À unciam latum ; scapus debilis, 4—6-uncialis, angulatus, basi 
brevi nuda, superne laxe racemosus ; flores minimi copiosi dissiti 
virides; pedicelli tenues 4 mm.; bractee minim: lanceolate; 
sepala linearia angusta acuta; petala angustissima linearia bre- 
viora; labellum hastatum acutum, auriculis majusculis rotundatis ; 
fovea nulla, lineis medianis 1-3 ; columna pro flore grandiuscula ; 
anthera majuscula oblonga. 
Mexico, Capt. Lyon! Sierra Madre, N.W. of Mexico, See- 
mann, 1957 ! 
‚6. M. ron PuynEA.— M. purpurea, S. Wats. in Proc. Amer. Acad. 
xviii. 1883, p. 195 ; Contrib. to Amer. Bot. xi. p. 195 (non Lindl.). 
Caulis 5-uncialis, basi paullo pseudobulbosa, vaginis obtusis 
purpurascentibus, tectus; folium singulum oblongum velovatum 
oblongum, acutiusculum, 3 uncias longum, 13 uncias latum; scapus 
basi j nuda, superne laxe racemosus, 7-9-uncialis; flores minimi 
purpurei, pedicellis gracilibus, 1-14 lineas longis ; sepala linearia 
oblonga, 14 lineas longa ; petala angustiora linearia breviora; la- 
bellum hastatum triangulatum acuminatum, fovea nulla, basi con- 
cava, linea elevata in medio ; auriculis minimis rotundatis ; columna 
grandiuscula, stelidiis obtusis rotundatis ; capsula rotundata ovata, 
2 lineas longa, suberecta. 
S. Arizona, Tanner's Cafion, Huachuca Mountains, Lemmon, 
no. 2881! Dr. Sereno Watson very kindly sent me a drawing 
and flowers of this plant. 
It is quite possible that this plant may be the species intended 
by Prof. Reichenbach under the name of M. Ehrenbergsi. His 
description, however, is insufficient to identify it with certainty, 
