18 



3. Chaetomorplia crassa (Ag.) Ktitz. 



Kltzing, Phycologia germanica, p. 204. 



— Tabulce phycologicae, vol. Ill, tab. 59. 



The form found had cells about 500 — 550 {jl thick. The 

 cells were nearly cylindric or sometimes a little inflated, mostly 

 a little shorter or as long as broad, but cells also occur about 

 twice as long as the diameter. 



Found once in shallow water near the shore intermingled 

 between Hypnea. 



St. Croix: Lt. Princess. 



Geogr. Distrib. Mediterranean, Atlantic coast of Europe. 



4. Chsetomorpha aerea (Dillw.) Ktitz. 



KiJTziNG, Species Algarum, 1849, p. 379. Collins, Green Algae of 

 North America, p. 324. 



A quite typical form, about 270 n diam., was 

 found at Lt. Princess, St. Croix, 



Some other loose-lying forms come near to 

 forma Linum, the diameter of the cells varying 

 about 250-300 /i. 



This species was found in shallow water only 

 and in more sheltered or quite sheltered places. 



St. Croix: Lt. Princess, Christiansted's Lagoon; St. 

 Thomas: Orkanoen, Store Nordside Bugt. 

 Geogr. Distrib. Extensive. 



5, Chsetomorpha brachygona Harv, 



Harvey, W. H., Ner. Bor.-Am., part 3, 1858, p. 87, 

 PI. XLVI, A. 



The specimens found had cells mostly nearly 

 as long as broad or a little shorter, more seldom 

 with the length 3 — 4 times the diameter. Cells 

 100—170 II diam. 



Ch. brachygona Harv. occurs often as large en- 

 tangled masses in shallow water in sheltered places 

 with loose, sandy or muddy bottom. It lies here 

 as a loose covering over the bottom or it is inter- 

 twisted among the sea-grasses growing here or 

 mixed with other more or less loose lying algaj: 

 Enteromorpha, Rhizoclonium etc. In the lagoons it 

 is found in even rather brackish water. In more 



Fig. 6. 



Ch(F{omorpha 



gracilis Kiitz. 



Part of a 



filament. 



About 100:1. 



