170 



Ectocarpus Rallsiae is evidently nearly related to Ectocarpus 

 conijerus and Ectocarpus irregularis. The most essential differences 

 are as follows: the frequently stalked sporangia, the shape of the 



plurilocular sporan- 

 gia, this being more 



cylindrical, tapering 



rather suddenly to- 

 wards the apex (comp. 

 M"« ViCKERS' fig. 1. c), 

 and also the distri- 

 bution of the sporan- 

 gia, these being placed 



anywhere upon the 

 filaments, much more 



irregularly than in 

 Ectocarpus coniferus. 

 Furthermore the fila- 

 ments in Ectocarpus 

 Rallsise are nearly all 



fairly uniform, rea- 

 ching a diameter of 

 about 27 ju. 



This species was only 

 found once, St.Tho mas: 

 Store Nordside Bugt. 



Geogr. Distrib. 

 West Indies. 



5. Ectocarpus 

 rhodochortonoides 



nov. spec. 

 Ectocarpus fila- 

 mentis erectis e filis 

 repentibus, horizont- 



alibus, irregulariter 

 flexuosis, egredienti- 

 bus instructus. 



Filamenta erecta, parce ramosa, 2^ ,« crassa, superne in pilum 

 transformata. Articuli in inferiori parte filorum usque ad 3 plo 

 longiores quam latiores, in pilis usque ad 14 plo. 



Sporangia plurilocularia sessilia, interdum breve pedicellata, 



Fig. 133. Ectocarpus Rallsise Vickers. 



a, part of thallus with phirilocular sporangia. 



b, filament with plurilocular and unilocular spor- 

 angia, c, cells in active state in the upper end 



of a hair, d, base of a plant, 

 (a and b, about 90 : 1 ; c and d, about 70: 1). 



