183 



Notes on some Florideje. 



By T. H. Bdfpham, A.L.S. 



(Taken as read January 17th, 1896.) 



Plate X. 



The following Notes may be considered as a continuation of 

 a paper On the Antheridia etc. of some Floridece, read in June, 

 1893 ("Journal," Vol. v., series ii., p. 241), as they refer 

 chiefly to the male organs of some of the red marine algae. 



Since then I have not been able to make a large addition to 

 the British records of these organs, but, such as they are, they 

 may not be without interest. None of the species now figured 

 have, to my knowledge, been drawn before, and most of them 

 have apparently escaped notice hitherto. When the present 

 names differ from those in Harvey's Phycologia Britannica, the 

 latter are placed in parentheses. 



Chondrus crisjpus Stackh. (Irish Moss) is one of our com- 

 monest species, and I have, through many years, unsuc- 

 cessfully sought for the antheridia. The male plant in no 

 way differs in habit from an ordinary barren specimen, and the 

 only indication of the difference is a faint sinuous line crossing 

 the frond a short distance below the apices, and seen most 

 readily on a half-dried plant. This line is the oldest boundary 

 of the antheridial layer which extends upwards in an irregular 

 patch, with here and there smaller spots, and fades off towards 

 the last divisions of the plant (Fig. 1). The surface view 

 differs very slightly from that of the ordinary cells of the 

 surface, and these male organs are certainly amongst the most 

 difficult of detection. Careful examination with a moderate 

 power at the edges of the frond where the layer occurs will 

 show a very narrow gelatinous border, but even this might 

 still leave the matter in some doubt. If a transverse section 

 through both the antheridial layer and the unchanged thallus 

 be taken the male organs are readily demonstrated. Fig. 2 

 shows the cells extraneous to the layer, and Fig. 3 those of the 



