48 ARKIV FÖR BOTANIK. BAND 1. 



The veins are arranged in the same manner as in Tr. 

 sphenoides, the costa being sometimes branched into a few 

 thicker veins, one for each lobe; yet, owing to its narrow 

 shape, in most fronds it is quite alone like a branchless 

 midrib, and all other veinlets are equal, slender, repeatedly 

 branched, and more or less flexuose or arcuate. The ulti- 

 mate venules are separated at the margin by 4 — 8 rows of 

 cells. 



The cellular structure does not seem different from the 

 preceding species of the sphenoides-group; fig. 25, D, E. 



On this plant I have found no fronds of roundish outline 

 and subüabellate venation, as in the two preceding species 

 (and in the two following also). 



The involucre is immersed to the lips. The marginal 

 hairs are shorter and finer than in Ir. sxihenoides. 



Hab. Brazil, S. Paulo, Sororocaba near Santos, >ad saxa 

 silvae primaevae», 20th May 1875, Mosén, n. 3810. 



11. Tricliomaiies myrioneuron n. sp. — Fig. 25 F— I; 

 28, 29. 



Syn. Trick, fruticulosum?? Jenmau, Gard. Chron., ser. 3, 1.5 

 (1894),*p. 71. 



The plant, which I now distinguish by this name, is of 

 the same external appearance as Tr. sphenoides, except as to 

 venation, for its venules are much more crowded than I have 

 found to be the case in any other species of Didymogloss\(m'. 

 Near to the margin the venules are so numerous and close 

 together, that it is difiicult in some cases to draw them se- 

 parate, if enlarged 20 times, even with a very fine pencil- 

 point. In this respect there seems to be no variation if full- 

 grown, fertile or sterile, fronds are regarded. The \;einlets 

 are mostly all similar; no thicker veins except the midrib. 



Like Tr. sphenoides, this produces sterile fronds of orbi- 

 cular form and subüabellate venation, fig. 28, B, and fertile 

 fronds of slightly larger size. The fertile blade is broadly 

 oblong, ovate, or obovate, with a short apical lobe, bearing a 

 single involucre, fig. 28, A, and 29. The base varies, as in 

 other species, from cordate to truncate, ovate, or broadly 

 cuneate. 



