THE GREEN ALGAE OF NORTH AMERICA 337 



A plant of the upper sublitoral zone, growing in warm, shal- 

 low bays, often in large quantities. Apart from the microscopic 

 characters, to which recourse must be had in mounted speci- 

 mens, the growing plants can generally be distinguished from 

 the nearest species, C. albida and C. gracilis, by the consistency 

 of the frond. C. albida is soft and spongy ; C. Rudolphiana soft 

 but not spongy ; C. gracilis, even in its most slender forms, has 

 a certain harshness to the touch. 



4. C. DEUCATULA Montague, 1850, p. 302 ; Kiitzing, 1856, 

 PI. I, fig. 2. lyoosely tufted, soft, dull green, about 10 cm. 

 high ; filaments 40-60 yu, diam. below, 4-6 diam. long ; loosely 

 branching, branches virgate, erect ; ramuli in short secund 

 series, seldom over 8 cells in length, cells 20-30 /* diam., 1-2 

 diam. long ; joints somewhat constricted. Florida, Jamaica, 

 Porto Rico, Cal. South America. 



A delicate plant varying in the amount of ramification, and 

 especially as to the frequency of the ramuli. 



5. C. VIRGATULA Grunow, 1867, p. 38. Fronds 7-10 cm. 

 high, soft, pale green, virgate, with subsimple main stem, beset 

 with long, erecto-patent, subsecund branches, issuing from 

 almost every joint ; connate for a short distance. Ramuli 

 simple or with a few subsecund ramelli ; cells of main axis 

 75-110 fj. diam., 3-6 diam. long; of the ramuli 45-55 .p- diam., 

 3-4 diam. long; of the ramelli 32-36 /* diam., 2-3 diam. long; 

 terminal cells subtorulose. Guadeloupe. 



The above is copied from Grunow's description ; the plant 

 resembles C. delicatula, but is larger. 



6. C. BRACHYCLADOS Montague, 18383, p. 15, PI. IV, fig. 2 ; 

 Harvey, 1858, p. 81. Filaments erect, 80-100 p. diam., primary 

 branches long, patent, with numerous appressed ramuli ; ulti- 

 mate ramuli very numerous, very short, secundly pectinate, ^o- 

 40 fj. dram.; cells in main filaments 5 diam. long, in ramuli 2 

 diam.; nodes contracted. Cuba. 



Resembling C. delicatula, but a larger plant, not so delicate, 

 with joints more uniformly constricted ; C. virgatula also seems 

 near it, but according to the description the latter has more 

 abundant main branches and fewer ramuli. 



7. C. POLYACANTHA Montague, 1850, p. 302 ; C. flexuosa 

 forma Floridana Collins, P. B.-A., No. 978. Tufts dull green, 

 10-20 cm. high; filaments dichotomous below, 50-80 /u, diam.; 

 branches long, rather stiff, flexuous, usually with naked apex, 

 elsewhere set with long similar branches, 30-50 /u diam., and 



