n6 Rhodora 



[June 



Le Jolis, Algues Marines de Cherbourg, p. 64. 



Hauck, Deutschlands Meeresalgen, p. 445. 



])e Toni, Sylloge Algarum, Vol. I, p. 335. 



Farlow, New England Marine Algae, p. 50. 



Hauck and Richter, Phycotheca Universalis, Nos. 13, 426. 



Collins, Holden and Setchell, Phycotheca Boreali-Americana, Nos. 

 224, 815. 



Conferva arcta, Dillwyn, British Confervae, p. 67, Plate E. 



Fronds rich green, in dense tufts, fastigiate, about 60-100 m diam- 

 eter, cells 4-6 diameters in the growing tips, 1J-3 diameters in other 

 parts of the frond ; erect, stiff, much branched, branches erect or 

 appressed, obtuse or clavate, giving off descending rhizoid-like 

 branches, 40-60/1 diameter, cells several diameters long, by which 

 the lower part of the tuft is firmly matted together. 



A spring plant, appearing as early as February in favorable local- 

 ities ; at first a bright rich green, becoming darker and duller in the 

 older plant. Found along the whole New England coast, it is more 

 common and luxuriant in the northern half, less from climatic con- 

 ditions than from the prevalence of exposed rocky shores, which are 

 its special habitat. At Newport, R. I., where favorable conditions 

 occur, it is abundant and luxuriant. 



In most of the references quoted above, the species is taken in a 

 wide sense, and would probably include C Sondcri and C. spinescens, 

 here considered distinct. The exsiccatae quoted, however, are C. 

 an/a as here understood. 



C. Hystrix (Stromfelt) De Toni. 



De Toni, Syll. Alg., Vol. I, p. 339. 



Spongomorpha Hystrix Stromfelt, Om Algvegetation vid Islands 



Kuster, p. 54. 

 ? C. Sondcri Kiitzing, Phyc. Germ., p. 208. 



Hauck, Deutsch. Meeresalg., p. 44. 

 ? Spongomorpha Sonderi Kiitzing, Tab. Phyc, Vol. IV, p. 17, 

 PI. LXXIX. 

 Fronds rich green, in rather dense tufts, filaments straight, branches 

 very erect, except in the lower part of the older fronds, where they 

 are more open ; about 100 /x diameter at the base, increasing in size 

 upwards, the end cell of the young, vigorously growing filaments 

 sometimes reaching a diameter of 250 p; cells generally one half to 

 one and one half diameters long, the terminal cell sometimes four 

 diameters. Rhizoidal descending filaments fairly common in the 

 older parts, 40-60 ft diameter, cells 3-10 diameters long. 



Resembling a luxuriant C. arcta, but the filaments are larger, the 

 cells shorter, the tufts less matted. It has been found at Newfound- 

 land, Isaac Holden ; Nahant, Mass., Peak's Island, Maine. 



The description given above is based on the Nahant and New- 

 foundland specimens, and does not agree exactly either with Strom- 



