954 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxvii. 



The sheet in the Prino-le herbarium at the University of Vermont 

 diii'ers only in its slig-htly greater breadth, the second and third pinna3 

 measuring about 12 cm. long. 



The species is quite distinct from known members of the group to 

 which it belongs. The most noticeable single character is its delicate 

 transparency, the texture resembling closely that of certain thalloid 

 marine alg.v which l)ecome extremel}' transparent upon drying. The 

 stipe is slight in thickness and relativeh' very short; the raised rachis 

 is, except in the terminal cauda, of a pronounced old gold color, as are 

 also the large sori; the midveins and initial venation of the pinna^ and 

 of the terminal cauda are blackish and raised. 



Pinna of Goniophlebiu-m pringlei (NAxrRAL size). 



The accompanying- text figure is a natural size illustration of one of 

 the fifth pair of pinnae of the type frond. It is from a print obtained 

 by placing the pinna directly upon sensitized paper and allowing the 

 sunlight to strike through the transparent tissue, and shows perfectly 

 the venation and the position of the orbicular sori. 



Two additional sheets in the United States National Herbarium dif- 

 fer in having the second pair of pinnae like the first, that is, free and 

 cordate-clasping at the base below the midvein and fully adnate above, 

 the adnate upper portion of the first pair overlapping the clasping 

 base of the second, there being only a very slight connecting foliar 

 wing along the rachis. In one of these (No. 460766), moreover, this 

 condition occurs in the case of the third pair of pinnw also, and the 

 foliar wing becomes well developed only between the third and fourth 

 pairs of pinnae and between succeeding pinna\ In all four sheets 

 examined the superabundance of leafy tissue, which must have given 

 a remarkable fluted appearance to the living fronds, is very noticeable. 



EXPLANATION OF PLATE XLVIII. 



From a photograpli of the type specimen, no. 460764 in the United State? National 

 Herbarium. About one third natural size. 



