3a, 
8a. 
9a, 
Pseudobulbs 2-leaved; sepals spathulate to oblan- 
ceolate, obtuse; petals elliptic, obtuse; spur of lip 
forward projecting under lip... .. . . .. . O.calcarata 
Pseudobulbs 1-leaved; sepals and petals lanceolate- 
elliptic, acute to subacuminate; spur of lip project- 
ing away fromlip. ......... .. .. O. Hebdingiana 
Sepals spathulate, obtuse; spur globose . . . O. spathulifera 
. Sepals obovate-oblanceolate, acute. . .......4.. 5 
Leaves sessile; sepals at least 14 mm. long; petals 
elliptic, acute; spurcylindric. . .... . . O. Decaryana 
Leaves petiolate; sepals not more than 8 mm. long; 
petals suborbicular, obtuse; spur subglobose, ven- 
trally compressed. . ... . 2. . « . OJ angustifolia 
Lip ecallose at base; basal Baise of 3 parallel veins 
of disc somewhat carinate-thickened . ... . - ee ee 
Lip with a bilobed callus, or bilamellate at or near Bee - » « 1S 
Pseudobulbs elongate, slender, fusiform to cylindric, 
2-3 leaved, approximately the length of the petiolate 
feaves or longer 4-5. we ew: eB a ae wwe me ee a 8 
Pseudobulbs short, ovoid, 2-leaved, much shorter 
than the petiolate leaves. . . A = 
Lip broadly elliptic; midlobe of lip senda: at oe 
overlapping with lateral lobes without a sinus; disc 
ecallose at junction of lateral and median lobes ..... 9 
Lip narrowly ovate-oblong to elliptic-oblong; midlobe 
of lip cuneate at base, forming a distinct sinus with 
lateral lobes; disc with a pair of fleshy gibbosities at 
junction of lateral and midlobes. . . . .. . . O.ugandae 
Midlobe of lip suborbicular in outline, half as long 
as the entire length of the lip; lateral lobes subfal- 
cate, obtuse at apex. .. . . « .  O, lanceata 
Midlobe of lip reniform in eee one- fourth the 
length of the entire lip; lateral lobes broadly 
rounded atapex ........... . . O.seychellarum 
Lip lobate from middle; lateral lobes of lip 
teunente in ont «6 6 «ow a 4: 4 ee ee ee oe DT 
Lip lobate one-fourth from apex; lateral lobes of lip 
OUUduE 1 TORE 6s a eG Se we RS De HS SB AB 
Lip wider than long; midlobe deeply emarginate to 
divaricately bilobulate in front . .. . . . .O. Lubbersiana 
Lip longer than wide; midlobe cuneate or with a 
distinct claw, at most retuse to indented in front O. pandurata 
Inflorescence laxly racemose; flowers greenish- 
[ 255 
