286 Alexander W. Evans, 



bergii Steph.^^ may be especially mentioned. The first of these 

 has a very extensive distribution and is reported by Stephani 

 from China, the Himalayas, Japan, Java and the Philippine 

 Islands; the second is known from various parts of India; the 

 third, from the Philippine Islands only. These three species are 

 closely related, and the differences brought out by Stephani are 

 not very convincing. As indicated in the synonymy the authors 

 of the Synopsis referred specimens of M. domingensis to M. 

 linearis, an error first pointed out by Stephani. Since, however, 

 M. linearis is so closely related to M. emarginata it will be 

 sufficient to compare the two American plants with this latter 

 species, a full description of which has been published by 

 Schiffner.^^ 



In size M. emarginata is comparable with M. domingensis; in 

 the structure of the female receptacle, with M. papillata. It 

 agrees with both species in the possession of sclerotic cells in 

 the thallus ; in the general features of the ventral scales ; in the 

 closely toothed appendages of the median scales ; and in the 

 structure of the involucre. Schiffner describes the latter as lobed 

 and almost entire, but it is sometimes possible to detect a few 

 short teeth, especially toward the outer extremities. A few dif- 

 ferences in the structure of the thallus may be mentioned. In 

 M. emarginata, for example, although sclerotic cells are present 

 they are never so abundant or so conspicuous as they sometimes 

 are in M. domingensis. The thallus is further distinguished by 

 the possession of slime cells and, according to Schiffner, by the 

 occasional presence of epidermal papillae. It would be unwise, 

 however, to lay much stress on any of these differences, since 

 the structures on which they are based are so very variable. 



The female receptacle of M. emarginata shows the features 

 described under M. papillata in an intensified form. The median 

 protuberance is not only more pronounced, but the lobes them- 

 selves might almost be described as costate, while their apices are 

 more markedly dilated and emarginate. These features are of 

 course subject to variation. The male receptacles are distin- 

 guished by their long and slender stalks. The cupules are much 

 the same as in two American species. 



'*' Bull. Herb. Boissler 7 : 524. 1899. 

 "Fl. de Buitenzorg 4:31. 1900. 



