-85- 



usually 4 than 5; a cross-section taken at the middle shows a row of about 100 

 single cells, the lower portion being 2 cells thick. The mouth is very small, 

 constricted and entire. 



Probably Mr. Pendleton will distribute specimens amongst his American 

 friends, but I shall be glad to send specimens to any student interested in the 

 species. 



// 



Aplozia Pendletonii Pearson 

 Fig. I. Bracts, with perianth, X 24. 



Fig. 2. Cross-section of perianth, about the middle, X 24. 

 Fig. 3. Mouth of perianth, explanate, X 50. 



PORELLA RIVULARIS (NEES) LINDB. 

 Wm. Hy. Pearson 

 Madotheca rivularis Nees, Nat. Eur. Leb. 3: 196 (1838). 

 Porella rivularis (Nees) Lindb. Muse. Scand. 3. (1879). 



Mr. James Murray of Carlisle, England, has recently sent me a Porella 

 from Portland, Oregon, which I have little hesitation in referring to the above 

 species: it is a very fine form, stems 2 to 3 inches long, distantly bipinnate; the 

 quadrate-oval, very decurrent underleaves scarcely wider than the stem, dentate 

 at their base, bracteole minutely denticulate; perianths numerous, produced 

 from the chief stem or branches, very large, with an extremely small mouth 

 which is irregularly jagged with a few one-celled teeth. The irregular mouth 

 of the perianth gives one the impression that it has been weathered, but 

 young perianths show the same character. 



The articles by Dr. Evans (Rhodora. 18: 79-85, 103-120. 1916) have been 

 particularly helpful to me in my studies of the American Porellae, of which we 

 have a very fine collection in the Manchester Museum. Owing to the War, I 

 have not seen Mueller's reasons (Rabenhorst: Krypt. Flora 6-: 585. 1915.) for 

 adopting the old name of Cordeana Hueben. for this species; seeing that Nees 

 (G. N. L. Syn. Hep. 282) quotes Cordeana Hueben, as a synonym for Porella 



