296 Transactions. — Botany. 



Fig. Pottia ohliqiia. 



1. Capsule and operculum. 



2. Perichsetial leaf (outer). 



3. Perichfetial leaf (inner). 



4. Stem leaves (upper). 



Pottia douglasii. 



1. Capsule and operculum. 



2. Calyptra. 



3. Perichsetial leaf (inner). 



4. Perichsetial leaf (outer). 



5. Stem leaf (upper). 



Art. XXIX. — Musci : Notes on the Genus Gymnostomum, 

 loith Descriptions of Neio Species. 



By Egbert Brown. 



[Read before the Philosophical Institute of Canterbury, 1st November, 



1893.] 



Plates XXXV.-XXXVII. 



The genus Gijinnostomum is distiuguished fi'om the other 

 aUied genera of mosses by its species being j^crennial, and the 

 cellular tissue of the upper portiou of their leaves beuig small 

 and dense ; also in the absence of a peristome. In the genus 

 Pottia, which is closely allied to it, the peristome is also 

 absent, but species of the latter are either annual or biennial, 

 and the cellular tissue is large and more succulent. In all other 

 respects these two genera are similar, having also the same 

 habitats, and being similar in appearance, which will account 

 for Mr. Charles Knight (in his description of certain mosses, 

 published in vol. vii. of the "Transactions and Proceedings 

 of the New Zealand Institute," p. 354) placing G. areolatumva. 

 the genus Gymnostomum instead of that of Pottia, to which, 

 from its large cell-structure, it probably belongs. These 

 mosses are generally found on damp banks, on the ground, 

 and are in fruit from October till February or March. Species 

 of both genera are often seen growing on the same bank. 



Since the publication of the " Handbook of the Flora of 

 New Zealand" I have discovered no record of any new 

 species of the genus Gymnostomum excepting Mr. Knight's 

 descriptions referred to above. It is to be regretted that 

 fuller details of some of these mosses were not given, as it 

 appears from the descriptions that two of them do not belong 

 to this genus, but to other genera. I have therefore not 



