t 

 * 



Coiitribution. I. 



131 



i"! ' 



Spongomorpha ceiitralis Kiitz. 1. c. t. 80. 



4 



Exsice, Confcrva arcta Arescli. Alg. Scand. exsicc. Nr. 129. 

 Cladophora arcta Åresch. L c. Kr, 334 et 335. ■ 

 Spongomorpha arcta AYittr. et Nordst. Alg. exsicc. Nr. 114, 316» 



413, 612. 

 Conferva centralis Wyatt, Alg. Danm. Nr. 46. 



f. penicilliformis Fosl. 



r 



in Wittr. et Nordst. Alg. exsicc. Nr. 613. 



f. Sonderi Ktitz. (nob.) 



Spee. Alg. p. 419. 

 Descr. Spongomorpha Sondeii Hauck, Meercsalg-. p. 444. 



i'W' 



tt 



.tf 



Kutz. Tab. Phyc. 4, p. 79. 



f. liystrix Stromf. (nob.) 



Dcscr. Spongomorpha hystrix Stromf. Isl. Algveg. p. 54. 



j 



Sy7z, Conferva arcta Lyngb. Hydr. Dan. p. 157. 



„ centralis Lyngb. 1. c. p. 161. 



r 



I have tåken the above mentioned typical form in a 

 rather wide sanse. Probably it may be divided into two 

 snhforms, a stricta B,j\å ^ centralis. Most nearly related to 

 it is, on the one side, the form that I have distribnted in 

 -Wittr. et Nordst. Alg. exsicc. Nr. 614 under the name 

 <>f f. pulvinata. It is easely recognized by its mode of growth, 



■ 



and very numerous rhizoids connecting the particular branch- 

 systems into dense masses. It of ten forms coherent mats 

 spreading widely over sandcovered rocks. I have seen snch 

 mats several hundred square foot in extent by a thickness 



4 



of 4 — 8 cm., and the siirface sometimes almost plain. On 

 the other side, the form im%iciUiformis is characterized by 

 its penicillated or thinly clustered frond, the branches being 



w 



6rect and rather rigid, in the lower part of the frond loose- 

 ly connected by numerous rhizoids. The main axis is at the 

 base usually thinner than high er up, in themiddle 100—140 

 P* thick, and chiefly upwards bearing pretty iew elongated, 



r 



'6^ect branches. The cells are generally 1 — 2 times more 

 '^ong than thick, The rhizoids, by this form only appearing 





i 



