In the same number of the Bulletin of the New York Botanical Gardens Mr. 

 Williams gives a very interesting report on the other mosses which he col- 

 lected in the Yukon region in 1898-99. In this account he describes several 

 new species, including two new Bryums, a genus even more difficult than 

 Brachythechtm. In our next issue I hope to give a full review of this paper. 



Plate V. — Orthotrichum Hallii. 

 Figs. I and 2. Peristome with part of capsule. 



Figs. 3, 4 and 5. Cross sections of leaf, from near apex, middle and base» 

 respectively. 



