46 ARKIV FÖR BOTANIK. BAND 1. 



the receptacle is exserted ont of the involucre (bearing^ 

 bright orange capsules when I gathered it); 



the marginal hairs are rather short, sparse and deci- 

 duous ; 



the caudex (rhizome) is extremely slender and almost as 

 line as a hair, about 0,2 mm thick; it is only sparsely covered 

 with short hairs. 



The cells of the frond are fairly large for so minute a 

 plant; the cellular structure resembles ihat of Tr. s2Jhenoides; 

 tig. 25, C. 



Hab. South Brazil, Rio Grande do Sul, Excolonia Santo 

 Angelo, on moss-clad stones round a little brook in the prime- 

 val forest, February 1893, Exped. 1. ßegnell., n. A, 1043. 



10. Trichomanes Mosenii n. sp. — Fig. 25 D, E and 27. 



The Herb. Regnell in Stockholm possesses abundant 

 specimens of a Didymoglossum, collected by Mosén near San- 

 tos and labelled by him as »nova species ?> I have examined 

 this plant carefully, and although the venation agrees with 

 Tr. sphenoides, 1 believe it is a proper species, distinguished 

 from Tr. sj)}ienoi(les by the following marks: 



the frond is generally very much extended, of linear, 

 narrowly lanceolate, or Ungulate form, or narrowly spathu- 

 late and in this case slightly lobed in a few short, not im- 

 bricate lobes; 



the base is in most cases extremelj'' narrowed or decur- 

 rent on the stipes the length of the whole blade; 



the size is considerable, the frond attaining 15 mm in 

 length (the stipes not included), hj 2 — 8 mm in width; 



the texture is very thin and transparent even in an 

 adult frond (by this mark it is at once distinguished even 

 from Tr. pnsillum Sw.), and pale or brownish green (gathered 

 in the autumn, May, but nevertheless bearing fronds in all 

 stages of development); 



the stipes is always well developed and naked, and the 

 caudex (or rhizome) only slightly hairy; 



the involucre is small, the lips of the same size as in 

 Tr. fontanum. 



