5 



Tetraspores are produced in ultimate find penultimate segments of 

 lateral ramuli ; they are arranged in a longitudinal nnv along the external 

 side or along both sides in two rows (in the latter case they aiv transverse 



are roundish and cruciate^r irregular]} tripartod. Oystocarps are formed 

 on the apex or at the side of ramuli. sessil, and are provided with simple 

 or forked. Hat involii' re-, embracing numerous neuclei. 



With respect to the structure of the frond in general, I am quite at 

 loss to see that there is no record about its minute details, as far as it is 

 known to me. In the diagnosis of 'Microdadia. given in Engler u. Prantl's 

 Planzenfamilien, for example, no minute description is given about the 



a broad rind which is internally constructed of larger and externally of 

 smaller cells. Also, Mr. Keinbold, in discussing about Gloioiliamnion, does 

 not give the details about the structure of Microdadia, only expressing 

 that GJoiothamnion does not present " eine scharfe ttcheidung in zwei 



deutlich gesonderte Schichten, wie das bei Microdadia der Fall, " 



From these lines, it seems to me that about the structure of Microdadia 

 it is only known that the cortex consists internally of larger and externally 

 of smaller cell. 



the central axis there are six cells which form the bases of branches ver- 

 ticillately arising trom the axis. In a longitudinal section cut parallel to 

 the surface, a row consisting of a few cells ascends obliquely from Loth -ides 

 of the axial cell, at the height half way up. Cells in that row are gradually 

 smaller upwards, and the ultimate ones form the cortical cellules; the re- 

 maining cells cut off minor ones towards both surfaces, and by further 

 divisions* they form cortical cells for the respective positions. This mode 

 of construction of the cortex will be best seen in Figs. 11 and 12 of 

 our plate. For the sake of comparison, I studied the structure of frond 

 of Microdadia borealts Ihtpr. and found it to be similar to the things 



Bemarlcs : The plant, of which I have so far described above seems 

 to me to be identical with Microdadia glanduhsa Grev. It appears more 

 so from Harvey's description and illustrations given in Phyc. Brit. tab. 29. 

 He remarks that " M. glandtdosa is often found tangled with other alga?, 

 upon which it grows ; and sometimes as Mr. Griffiths observes, creeps over 



