8o TUFTS COLLKGB STUDIES, VOL. IV, No. 7 



10. C. GRACIUS Kutzing, 1845, p. 203; 1853, p. 17, PI. 

 LII, fig. I; Borgesen, 1913, p. 19. Filaments 40-70/4 diam., 

 cells 2-4 diam. long. Loosely floating, W. I., Bermuda. 



Europe; Singapore. 



11. C. MINIMA Collins & Hervey, 1917,?. 41, PI. I, figs. 5-7 ; 

 P. B.-A., No. 2007. Filaments cylindrical or slightly clavate, 

 short, 10-20 /* diam., cells 2-4 diam. long ; membrane relatively 

 thick and lamellate ; on larger algae. Bermuda. 



Page 330, under RHIZOCLONIUM CRASSIPELI.ITUM, note, 



The typical form has been found at Bermuda, and distributed 

 as P. B.-A., No. 2008; also at Holland, Mich., Transeau. 



Page 332, in Key to the marine species of Cladophora, make 

 changes and additions as follows : 

 For Nos. 1-5, 



I. Low, pulvinate or matted, with main filaments more or less pros- 

 trate. 2. 

 i. Erect. 6. 

 2. Lower part of filament! 300-350 n diam. 41. < '. mteite \ta. 

 2. Lower part of filaments less than 300 M diam. 3. 

 3. Branching mostly irregular, not dichotomons. 4. 

 3. Branching mostly di-trichotomous. 5a. 

 4. Erect branches distinct from prostrate filaments and smaller. 5. 

 4. No sharp distinction between different kinds of filaments. 



37. C. Magdalenae. 

 5. Basal filments 150 M diam.; erect filament* 20-50 M diam., cells 5-20 



iliatn. long. 38. C. ffowei. 



5. Basal filaments 40-100 M diam. ; erect filaments 30-50 n diam., cells 



4-8 diam. long. 40. C. amphibia. 



5a. Cells cylindrical or nearly so ; color dark. 58. C. repens. 



5*. Cells of ramnli ovoid or pyriform. 5b. 



Sb. Cells 120-250 M diam. 39. C. trichotoma. 



50. Cells 60-100 M diam. 59. C.frascatii. 



For No 10, 



10. Cells with more or less regular constrictions: IOA. 



10. Cells without regular constrictions. 20. 



loa. A single constriction near base of cell. la. C. constricta. 



ioa. Frequent constrictions of cells of main axes; ramuli often hooked 



or circinate. 54. C. uncinata. 



For No. 30. 

 30. Branches often decumbent ; rbizoidal branches numerous. 



55. C. corallicola. 

 30. Not decumbent ; rhizoids few or none. 30*. 



