1902] Collins, — Marine Cladophoras of New England 125 



Farlow, N. E. Marine Algae, p. 52. 



Farlow, Anderson & Eaton, Alg. Am.-Bor. Exsicc., No. 207. 



Collins, Holder) & Setchell, Phyc. Bor.-Am., No. 573. 



C hamosa var. refracta Hauck, Deutsch. Meeresalg., p. 457. 



Hauck & Richter, Phyc. Univ., No. 272. 



? Conferva refracta Roth, Cat. Bot., Vol. II, p. 193. 



Filaments rather stiff, 40-120 /x diam., articulations 2-3 diam., 

 glaucous green ; branches flexuous, the secondary branches and 

 those of subsequent orders at first erect, then rerlexed ; ultimate 

 ramuli often secund, blunt. 



A common form in rocky pools throughout our whole range, and 

 not very variable. It has a characteristic habit, not easy to describe, 

 but recognized without much difficulty, even in mounted specimens, 

 when once known ; but forms of C, flexuosa sometimes resemble it 

 pretty closely. 



There is uncertainty as to what Conferva refracta Roth really 

 was, but the Cladophora refracta of Areschoug seems to be a fairly 

 distinct species, while the C. refracta of French algologists is appar- 

 ently a variety of C. albida. 



C. rupestris (L.) Kiitz. 



Ktitzing, Phyc. Gen., p. 270. 



Harvey, Phyc. Brit., PI. CLXXX ; Nereis Bor.-Am., part 3, p. 74. 



Le Jolis, Alg. Mar. Cherb., p. 63. 



Farlow, N. E. Marine Algae, p. 51. 



Hauck, Deutsch. Meeresalg., p. 4^2. 



De Toni, Syll. Alg., Vol. I, p. 328. 



Collins, Holden & Setchell, Phyc. Bor.-Am., No. 728. 



Conferva rupestris Linnaeus, Syst. Nat., Edit. 12, Vol. II, p. 721. 



Filaments dark green, 80-150 \x diam., articulations 3-4 diam.; 

 fronds densely tufted, much branched, the branches opposite or in 

 fours, erect, ultimate ramuli short, blunt or slightly subulate. 



In the confusion that exists in this unhappy genus, it is pleasant 

 to find one species about which there can be no mistake, and C. 

 rupestris is nearly unmistakable, with its dense, dark, stiff tufts 

 with opposite or whorled branches. It is a rather handsome plant 

 while growing, but herbarium specimens seem coarse, and do not 

 adhere well to paper. It grows on rocks near low water mark, often 

 covered by Fuci, and seems to be in good condition all through the 

 year, while most Cladophoras are spring and summer plants. It is 

 common from Nahant north, and is also found at Gay Head, 

 Farlow. 



The plant is figured and described by Harvey as having subulate 

 ramuli, but in most American specimens examined the ramuli are 

 blunt; in a few cases only are they slightly acuminate. 



C. laetevirens (Dillw.) Harv. 



Harvey, Phyc. Brit., PI. CXC ; Nereis Bor.-Am., part 3, p. 66. 



