MARINE ALGAE FROM EASTER ISLAND 



3°5 



all from the European Atlantic coast and the Mediterranean Sea. Most likely 

 therefore the present plant is the representative of a new species. In order to 

 describe it we must know at least also the tetrasporic plant, as the male plant 

 in Nitophyllum is often very much reduced in size. 



Gymnogongrus Mart. 



G. aequicrassus nov. spec. ■ — Figs. 46, 47. 



Frons caespitosa, e fills decumbentibus, repentibus et fills erectis composita. 



Fila decumbentia irregulariter ramosa, aggregata et inter se contexta. 



Fila erecta teretiuscula, interdum simplicia saepe di- vel trichotoma, ad 

 apicem versus non attenuata, apex late rotundatus. 



Cystocarpia singulas apicibus frondis immersa, rotundata, superne in partem 

 sterilem attenuatam exeuntia. 



Fig. 46. Gymnogongrus aequicrassus nov. spec. 

 C. «/i. 



Fig. 47. Gymnogongrus aequi- 

 crassus nov. spec. Length sec- 

 tion of thallus, c. 45 %- 



The plant grows gregariously in dense tufts about 2 — 3 cm high upon 

 rocks between tide marks. 



The tuftlike growth originates from the numerous erect filaments growing 

 out from the prostrate creeping ones. The latter filaments are irregularly bent 

 and branched, gradually more or less united into an irregularly lobed disc. The 

 erect filaments are nearly terete or somewhat compressed, the transverse section 

 being mostly oval. The filaments are a few times dichotomously, rarely tri- 

 chotomously forked, but quite simple ones also occur. The surface of the 



20 — 2391. The Nat. Hist, of Juan Fernandez and Easter Isl. Vol. II. 



