80 



Dansk Botanisk Arkiv, Bd. 3. Nr. 1. 



In about the middle of the assimilating filaments vigo- 

 rous carpogonial branches are found (Fig. 83 a, b, c) ; these are 

 nearly straight and placed laterally near the upper end of the 

 almost cylindrical cells found here. Besides the carpogonial 

 cell with its long trichogyne, it consists of three or four, rarely 

 five cells. These have rather thick walls, are mostly shorter than 

 long and a little swollen in the middle ; their diameter reaches a 

 length of about 20—27;/, The shape of the carpogonial cell is 

 short conical ; it has rather thick peripheral walls. The full 



grown trichogyne is nearly cy- 

 lindrical, often somewhat irre- 

 gularly bent towards the sum- 

 mit, and a little thicker here; 

 when young it is seen as a 

 short obovate outgrowth from 

 the carpogonial cell, later, on 

 gradually growing longer, it 

 assumes a clavate appearance 

 and becomes at last nearly 

 cylindrical. 



Having only found a very 

 few fertihzed carpogonia show- 

 ing later stages I have not 

 been able to follow the development in more detail. The youngest 

 stage found is shown in fig. 85 a ; we see here the outgrowth of 

 the sporogenous filaments. Fig. 85 b shows a more advanced 

 phase and in fig. 85 c is portrayed a nearly ripe cystocarpium. 

 As is the case in other species so here the fertihzation of the 

 carpogonium exerts an influence upon the cell from which the 

 carpogonial branch is issued and also upon some of the neigh- 

 bouring cells; from these numerous filaments grow out more or 

 less surrounding the basal part of the cystocarp. 



Vegetative filaments were found several times in this species 

 growing out from not fertihzed carpogonial branches. Such out- 

 growths were either lateral from the cell below the carpogonium 

 (Fig. 86 c) or terminal from the carpogonium itself (Fig. 86 d). 

 In this species I have not succeeded in finding antheridia. 



Tliis plant has only been found once in shallow water at Long Point 

 at the south coast of St. Croix. 



6. Liagora pulverulenta C. Ag. 



Agardh, C, Species Algarum, 1821—2, p. 396. Agardh, J., Epicrisis, 

 1876, p. 516; Analecta Algologica, Continuatio III, 1896, p. 101. 



Fig. 86. Liagora megagyna nov. spec. 

 a, b, development of the trichogyne. 

 c, d, carpogonial branches producing 

 vegetative filaments, (a, b, d, about 

 160 : 1, c, 60 : 1). 



