1921] Lewis & Taylor,— Notes from Woods Hole— 1921 251 



The chloroplast may be either lobed or a continuous cylinder in both 

 forms. Furthermore, bothare catharobic, requiring organic adjuvants 

 to the brackish water in which they live. There are two notable 

 differences. First, Prasinocladus has been found only in late fall or 

 winter in this locality, while Vhdymonas has been observed only in 

 summer. Second, Platymonas is free swimming, while the cells of 

 Prasinocladus are united to form a gelatinous colony. 



There is here a problem still to be solved, but to the writer the 

 probabilities strongly favor the view that Platymonas is the motile 

 stage, Prasinocladus the "Palmella" stage of the same organism. 



Opposed to this view is the negative result of culture. Platy- 

 monas was isolated on agar and kept for over twelve months under 

 continuous observation. Samples were removed and cultivated in 

 sea water under varying conditions. The unicellular condition was 

 persistently maintained and the pseudofilamentous habit of Prasino- 

 cladus was never assumed. Observations under natural conditions 

 will be required before a final judgment can be given. — T. F. Lewis. 



Platymonas subcordiformis (Wille) Hazen, comb, now Carteria 

 subcordiformis Wille, Nyt. Mag. f. Naturvid. 41: 93, 94. 1903. It 

 may be worth while to record briefly the history of the identification 

 of this species. During a visit to Woods Hole in August 1919 Dr. 

 Lewis conducted me to his station for Platymonas at Black Rock, 

 where abundant material was secured. Later in the season I found 

 the same species in less amount at Twin Island, Pelham Bay, New 

 York. Early in the summer of 1920, while spending a week at Aale- 

 sund, Norway, where Professor Wille had discovered several interesting 

 Chlamydomonads in 1902, I collected a form which was at once 

 recognized as very similar to, if not identical with, that to which Dr. 

 Lewis had introduced me. I was also struck with the resemblance 

 of this form to Carteria subcordiformis, especially when comparison 

 was made with the original drawings of the latter a few days later. 

 Upon examination of my freshly collected material, Professor Wille 

 readily identified it with his species, which appears not to have been 

 reported since the original discovery. I later found the same species 

 at Cullereoats, near Newcastle-upon-Tyne, and at Plymouth, Eng- 

 land. In September 1920 I again collected the species at Nahant, 

 Mass., and also at Fort Phoenix, Fair Haven, Mass., not far distant 

 from the station on Black Rock, and again ;it Pelham Hay. I have 



