288 Transactions. — Botany. 



Plate XXXb. 



Macromitrium retusum, H.f. and W. 



Fig. 1. End of branch, x 32. 



Fig. 2. Comal leaf, with hair-point uninjured, X 32. 



Fig. 3. Leaf with hair-point partially broken off, X 70. 



Fig. 4. Lower leaf, back view, with " retuse " apex, the bristle 



broken off. 

 Figs. 5, 6, 7. Leaves copied from " Flora of New Zealand," 



t. 85, f . 6. 



Plate XXXc. 



Anisotheciiim gracilliimmi, sp. nov. 



Plant nat. size. 



Fig. 1. Leaf, x 70. 



Fig. 2. Apex of same, x 270. 



Fig. 3. Cells from middle of leaf, X 270. 



Fig. 4. Perichcetial leaf, x 70. 



Fig. 5. Capsule and operculum (immature), X 32. 



Fig. 6. Capsule, ripe, x 32. 



Fig. 7. Male infloresence, x 32. 



Abt. XXYIII. — Notes on Neiv Zealand Mosses : Genus Pottia. 



By E. Brown. 



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



1893.] 



Plates XXXI.-XXXIV. 



The species composing this genus may be readily distinguished 

 from those comprised in Gymnostonmrn, as the former are 

 either annual or biennial plants, and the leaves have large 

 cellular tissue. 



The members of this genus appear to have been entirely 

 overlooked by botanists, as witness the Rev. J. Berkeley, who, 

 in his introduction to " Cryptogamic Botany," actually says, 

 " This genus does not occur in Neio Zealand." This may pos- 

 sibly be accounted for by the minuteness of the plants, also 

 by the short time it takes them to arrive at maturity. 



They are to be found growing on steep damp clayey 

 banks, where the earth during the hot summer months 

 crumbles away, leaving a fresh surface for the spores of those 

 plants to germinate on during the following winter ; as their 

 vigorous growth takes place only on freshly-turned soil, too 

 much organic matter in the soil does not suit them. They 

 speedily become extinct in those habitats ; when this takes 

 place a higher class of vegetation follows ; they therefore 

 form a section of the pioneers of vegetable life. 



