﻿1. Polytrkhum commune L. 



Folia plana, margine suberecto, et a cellulis irregula- 

 riter quadratis, haud prominentibu», et a cellulis decem — duo- 



lis, obliquis, subretortifonnilms et, ut Herraturis, prominenti- 

 bus constructo; in sectione transversa anguste semilanceo- 

 lata, angulis obtusiusculis, nervö latissimo, applanato, dorso 

 haud prominente. Lamelke creberrimre, circiter 60. humiles, 

 sat densre, rectre, ab uno strato (4 — (i) eellulannn constructre, 



loso-dentatre, cellula inarginali. in sertinne t rsius^ cr>a. paulln 

 majore, sed latiore, supra impressa, subquadratu-seiniluuan 

 et ubique sat conformiter incrassata. 



* P. cubicum Lindb. 



Folia plano-canalifiihtln . margine gpeciei typicre; in 

 sectione transversa seiuiluuaria, angulis obtusis, dorso nervi 

 indistincte prominente. Lamelhv crebrse, circiter 48, altio- 



* P. Swartzii Hartm. 



Folia plano-canaliculata, margine speeiei tvpicre: in 

 sectione transversa anguste plano-semilunaria, angulis acu- 

 tiusculis. dorso nervi prominulo. Lamelloe sat erebrre, circiter 

 42, altiores, sat remotre, margine integir®, cellula oiwginaH, 

 in sectione transversa, supra vix impressa, subseniilnnari 

 — triangulari. 



b) Cellula marginalis lamelire, e latere visa, apice 

 abrupte elongata et unipapillo.so-dentata et, in sectione trans- 

 versa lamellre, cruci- vel lagenreformis. Folia margine in- 

 voluta, plus minusve integerri 



