F. Borgesen : Rhodophyceæ of the Danish W. Indies. 



65 



imens was red-brown in contrast to the more dirty yellow-brown 

 in N. Schrammt. 



As to the anatomical structure, this species consists in 

 the interior of nearly colourless, long-celled, hyphæ-like, thick- 

 walled cells running mostly in a vertical direction, interwoven and 

 from 3 — 14 ;M thick. Near the periphery they are more richly 

 ramified and bear here the horizontal assimilating filaments which 

 radiate outwards in small bundles and branch dichotomously (Fig. 

 66 A). Innermost at the transition from the medullary tissue 

 the cells are rather long and nearly cylindrical but they grow soon 

 shorter and at the same 

 time become swollen in 

 the middle in such a way 

 that the cell-threads be- 

 come moniliform, reaching 

 a thickness of about 13 — 

 14;/. Compared with N. 

 Schrammt the cells are 

 somewhat slender. 



The chromatophore 

 (Fig. 66 C) is stellate and 

 resembles very much that 

 of N. Schrammt though as 

 a general rule it only fills 

 half the cell ; of the outer- 

 most ones nearest to the 

 periphery it occurs at the 

 top, while it is found in 

 about the middle of the 

 slender and more cylin- 

 drical cells further in. In 



the middle of the chromatophore a pyrenoid is present. Having 

 only dried material for examination I have not succeeded in finding 

 the nucleus. 



In the middle of each of the peripheral bundles of assimil- 

 ating filaments a single cystocarp occurs (Fig. 66 A, B); it is 

 very rarely that a second one develops on a side-branch. 



While in N. Schrammt nearly all the material was in the 

 stage of development mentioned above, viz. with the trichogynes 

 still present, in Nemalton longtcolle nearly all the material had 

 ripe cystocarps. These are terminally placed on a rather long 

 straight branch, the cells of which are shorter and nearly cylindrical, 



Dansk Botanisk Arkiv, Bd. 3. Nr. 1 (1915). 6 



Fig. ßß. Nemalionlongicolle Børgs. .4, bundle 

 of assimilative filaments in the middle of 

 which the cystocarp (140:1). B, another 

 cystocarp (140:1). C, cells with chroma- 

 tophore and pyrenoid (250: 1). D, carpo- 

 gonial branch with trichogyne (140: 1). 



