1921] Lewis & Taylor,— Notes from Woods Hole -1921 249 



peat bogs, but not in the soil conditions necessary for Thuja, and Thuja, 

 as Professor Fernald well remarks in his article, will grow in habitats 

 either boggy or well drained, but not in the soil conditions, whatever 

 these may be, required by Plnus Banksiana. To this extent, then, 

 my observations appear to corroborate the conclusions of Professor 

 Fernald. 



Urban a, Illinois. 



NOTES FROM THE WOODS HOLE LABORATORY,— 192J. 

 I. F. Lewis and W. R. Taylor. 

 (Plate 133) 



Platymonas suhcokdifokmis (Wille) Hazen. — In the summer of 

 1917 a unicellular green organism was found in a small tide pool on 

 Black Rock, near the entrance to New Bedford Harbor. It was 

 considered to be a new American species of the genus Platymonas 

 West 1 until Dr. Tracy E. Hazen established and called attention to 

 the fact that it is identical with Wille 's Caricria subcordtformis. 2 Dr. 

 Hazen 's account is reproduced at the end of this note. 



The organism has been found in each succeeding summer in the 

 same locality, and Dr. Hazen records its occurrence elsewhere in 

 Massachusetts and in New York, as well as in England and Norway. 

 At the Black Rock station it has been consistently abundant in certain 

 pools. The rock is a haunt of gulls, and the water containing the 

 Platymonas is at times so fouled with excrement as to give off a 

 decidedly unpleasant .odor. It seems, like certain other Chlamy- 

 domonads, to flourish best in the presence of organic pollution. It 

 can endure a range of salinity from that of almost fresh, or quite 

 fresh (Wille), water to that of sea water. 



The cells are small, varying in length from 13 to 17 ;jl, in breadth 

 from 7 to 8 [i, in thickness from 4 to 5 ;jl. In surface view (pi. 133, figs. 

 1-3) the cells are oval and flattened. One face is convex, while the 

 other is nearly flat (fig. 4). 



The usual vegetative phase is actively motile with the anterior end 



1 West, ('.. S. AU?ok>Kie;iIiiotesXYIII-XXIIl. Journal of Botany 54: 1-10. l<)l(i. 

 - Wille, N. Algologische Notizen IX. Ueber eine Art dor Gattung Carteria 

 Diesdng. Xyt. Mag. Natnrvid. 41: 89-94, Taf. :{. 1903, 



