— 20 - 



exterioribus ramosis, fascia longitudinal! late lineari incrassata interne un- 

 gue paulo angustiore supra basin abrupte terminante paulo dilatata sub- 

 truncata leviter retusa et papillosa, in inedio labelli obselete marginata, in 

 lobo média bene elevata apicem non attingente apice vix dilatata et trun- 

 cata, totum explanatum c. 0.65 cm. longum, bene 0.7 cm. latum, ungue c. 

 0.23 cm. iongo, 0.14 cm. lato, lobis lateralibus recurvis, convexis, 

 oblique quadrangulis, oblique angulato-rotundalis, basi paulo angus- 

 tatis, apice irregulariter crenulatis. c. 0.275 cm. latis, lobo medio 

 minore, latérales paulo superante, quadrangulo, apice subrotundato-truncato, 

 convexo, denticulato, c. 0,17 cm. Iongo, 0.17 cm., basi bene 0.2 cm. lato. 

 Gynostemium subrectum, a dorso compressum, dorso convexum, apice in 

 utraque stigmatis parte in stelidium elongatum porrectum falcalo-decurvum 

 subulatum intus carinatum triquetrum satis acutum margine superiore supra 

 basin dente (auriculo) donatum inexplanatum c. 0.26 cm. longum productum, 

 bene 0.4 cm. longum, apice producto cum gynostemio anguium obtusum 

 faciente, incurvo, dorso convoxo, quadrangulo, truncato. Anthera plane 

 cucullata, quadrangula. paulo latior quam longa, apice leviter retusa, papil- 

 losa, fere 0.14 cm. lata. Rostellum porrectum, latuni, truncatum. Stigma 

 transverse quadrangulum. Pes gynostemii abbreviatus. Ovarium leviter 

 6sulcatum. c. 0.5 cm. longum; pedicellus paulo tenuior, c. 0.35 cm. longus. 



Banka: Koba, Goenoeng Pading, 170 m., on dead wood in forest; rare. 

 (H. A. B. BuNNEMEijER n. 2169, December 1917). 



Sumara: Goenoeng Talamau on the u'estern slope, 600 m., in forest. (H. A. 

 B. BiJNNEMEijER H. 559, May 1917). 



1 hâve always been of the opinion, that Leucolaena Ridl. should be 

 merged in Didymoplexis Griff. Since 1 hâve been in the position to exa- 

 mine a species of this genus and since there hâve been found a few 

 species of Didymoplexis (D. obreniformis J. J. S., D. Jlexipes].].S),vj\\\z\\ 

 may be regarded as transitory links, this opinion has been confirmed. 



The only différence between Didymoplexis and Leucolaena is, as far as 

 1 could trace, formed by the elongated stelidia of the column. In the 

 two species of Didymoplexis cited above, especially in the former one, the 

 stelidia are represented by conspicuous triangular lobes, hence the différ- 

 ence becomes only a graduai one. 



The 3 species of Didymoplexis with elongated stelidia, viz D. ornata 

 (Ridl.) J. J. S., D. borneensis (Schltr.) J. J. S. and D. Trichechus J. J. S.,, 

 may perhaps constitute a section Leucolaena. 



D. Trichechus differs from D. ornata in the very much broader sepals and 

 petals, the larger very obtuse midlobe of the lip surpassing the side- 

 lobes, and the column having a much shorler and broader filament, shorter 

 stelidia and a quadrangular much broader anther, and from D. borneensis 

 in the larger flowers, the dorsal sepal being adnate to the petals only 

 in the lower half, whereas also the latéral sepals are only connate 

 halfway, the broadly ovate petals, the much broader lip v^ith obliquely qua- 

 drangular not scmiorbicular side lobes and a quadrangular very blunt midlobe. 



