4 Dansk Botanisk Arkiv, Bd. 2, Nr. 3. 



poisonous species of sect. I have globular spores. — The spore- 

 membrane is always smooth. 



The number of spores on each basidium, in all the species 

 examined by me, is the ordinary 4. Only an American species, 

 A. bisporigera Atk., is reported as having 2. — The edge of the 

 gills often (always?) is set with sterile cells (cystidia), which 

 generally are subglobular, in some cases cylindric-vesiculose. 

 But as far as I can see they are of less importance than the 

 spores for purposes of classification. 



The universal veil, which macroscopically presents so 

 marked differences (being membraneous, granular, mealy etc.), 

 is generally made up op two types of cells: globose large cells 

 and narrow cylindric ones, which form slender filaments. But 

 the microscopic examination — even of species so different as 

 A. Mappa, A rubescens and A. vaginata — does not materially 

 aid us in discerning the difference in veil-structure: Even the 

 granulated veil does not solely consist of globular cells — as 

 might be expected — but also of filaments. 



Spores etc. of all the species are figured on Plate II. 



The Key given below is based on the microscopic as well 

 as on the macroscopic characters of the species, and comprises 

 all the species found by me. 



