BuowN. — On the Genus Pottia. 289 



The best time for their successful collection is in wet or 

 very damp weather, for on other days their leaves are gene- 

 rally curled up and appear dead, and then it is with great 

 difficulty that they are discovered. 



The fii-st record of any species belonging to this genus 

 having been discovered in New Zealand which I have been 

 able to find is that one described by Mr. Charles Knight as 

 Gymnostomum areolatum in vol. vii., Trans. N.Z. Inst., 

 p. 355. 



In another paper I have pointed out the anomalous posi- 

 tion this particular moss {G. areolatum) holds, and proposed 

 to place it in the genus Poito, as being more in harmony with 

 its character. 



The only other species which is said to belong to the 

 genus Pottia is one described by Mr. T. W. Naylor Beckett 

 in a paper contributed to the Philosophical Institute of Can- 

 terbury on the 5th October, 1892, and recorded in vol. xxv., 

 p. 290, of the Trans. N.Z. Inst., and there named by him 

 P. marginata. 



This plant has no actual existence, being a combination of 

 a new species previously described by me in a paper read 

 before the Philosophical Institute on the 7th September, 

 1892, and recorded in vol. xxv. of the Transactions, p. 286, 

 and there named Hennedia microphylla, and a new species of 

 this genus Pottia. 



The points of resemblance between these two species are 

 many, both being found in the same situations, growing to- 

 gether in the same patches, having very similar leaves, 

 and bordered margins. Here, however, the resemblance 

 ends; H. micropliylla having a simple stem, a mitriform 

 calyptra covering the whole capsule tightly, and nar- 

 rowed at the base ; the Pottia having a cucullate calyptra, 

 and only covering about one-half of the capsule. The 

 cell tissue of the former is at least double the size of the 

 latter. The capsule of the former has a straight, short, stout, 

 conic operculum, while that of the latter has a long oblique 

 one. It is unfortunate that Mr. Beckett has confounded 

 these two species, as it necessitated his formulating a new 

 development theory to explain his description of this moss. 



He knew that I had previously described this moss with 

 the mitriform calyptra as H. microphylla, and, as he has 

 attempted to give this moss a new generic and specific 

 name, and has omitted to make any reference to H. micro- 

 Ijhylla, I am very reluctantly compelled, in order to prevent 

 any confusion, to put this matter straight. 



I should like to have called the new species of Pottia, 

 which he has confounded with Hennedia microiohylla , Pottia 

 marginata, in Mr. Beckett's honour ; but, as under the cir- 

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