ORCHIDACE.E 



triangulari-lanceolata, acuta, ad apicem breviter carinata, cum 

 mento 1.4-1.5 cm. longa, extus dense pilosa. Sepalum dorsale 

 anguste lanceolatum, concaviusculum, circiter 12 mm. longum, 

 quam sepala lateralia multo angustius, extus dense pilosum. Pe- 

 tala linearia, obtusa, sparse hirsuta extus, circiter 1 cm. longa, 

 vix 2 mm. lata. Labellum trilobatum, e basi cuneatum, 12 mm. 

 longum ; lobi laterales parvi, rotundati, denticulati ; lobus medius 

 orbicularis, vel subquadratis, ad apicem retusus cum mucro, den- 

 ticulatus, 3-3.5 mm. longus. Totum labellum extus glabratum 

 et per medium carinatum, intus ecarinatum, pilosum praesertim 

 in lobo medio. Mentum obtusum 5 mm. longum. Columna cum 

 operculo et pede circiter 1 cm. longa. 



From Eria halconensis Ames, E. McGregorii is easily distin- 

 guished by its larger flowers. From E. odorifera Leavitt, where 

 dried specimens are considered, it is separable by the verrucu- 

 lose foliage and closely appressed rather than spreading pubes- 

 cence. It also differs from E. odorifera in its denticulate labellum 

 lobes and in its longer racemes. In proposing McGregor's mate- 

 rial for specific rank I have relied wholly on dried specimens and 

 on a careful study of the types of E. halconensis and E. odori- 

 fera, which among the species of §Trichotosia appear to be most 

 closely allied with E. McGregorii. 



The Trichotosia section of the genus Eria is at present known 

 to contain nine species which are natives of the Philippine Is- 

 lands. With the exception of E. Ramosii Leavitt, a dwarf species 

 with distinctly creeping habit and with small leaves about 8 mm. 

 long, they are extremely difficult to differentiate if reliance is 

 placed on descriptions alone. The following key, based on a re- 

 study of herbarium material, is offered with the hope that it may 

 show the important characteristics serviceable for differentiation 



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