342 T. H. BUFFHAM ON THE FLORIDE.E AND 



are to be found in pairs, triplets, and clusters, all rising from 

 one cell of the ramulus. To make up by numbers for lack of size 

 I may mention that in one field of a diameter of *03 inch I have 

 counted as many as 80 antheridia. 



Near the same place I collected a very brightly coloured specimen 

 of Griffithsia corallina which on examination was found to have 

 antheridia clustering round the filament at the junction of two 

 cells. With a power of 25 it appears as in Fig. 3. With \ inch 

 x 200 each antheridium is seen to be a highly complex and 

 beautifully symmetrical body, composed of a vast number of colour- 

 less antherozoids on semi-transparent branches. For clearness it is 

 drawn as it would appear when separated from the filament. With 

 i inch x 800 the antherozoids are found to be pear-shaped and 

 pointed, and show indications of some kind of granulation. 



Most persons are more or less familiar with Ptilota elegans 

 (sericea of Harvey) as a microscojnc object. In its barren state, 

 when luxuriantly grown, it is, under the microscope, perhaps 

 the handsomest alga of our shores. I have, however, observed 

 that it seldom has fruit when the plumules are recent and symme- 

 trically grown. It seems to require age before it fruits. In 

 a gathering of the plant with favella3 (cystocarps) I found a small 

 tuft bearing few of this form of fruit, but several procarps with their 

 trichogynes, and on the pinnules a large number of bodies that 

 I cannot doubt are antheridia. They occupy the positions where the 

 tetraspores are usually found, that is, terminal, or nearly so, on the 

 ultimate ramuli, and are composed of a number of minute granules or 

 cellules of pale colour. They are most likely immature, as the 

 antherozoids can scarcely be well seen, although the exterior of 

 some of the antheridia seems breaking up in the usual manner ; 

 \ inch x 200 shows them as in PI. XII., Fig. 1. 



Perhaps the most ubiquitous of the red alga? is Ceramium rubram. 

 The cystocarps are extremely common, yet antheridia have, 1 

 believe, never been found on our coasts. I have been fortunate in 

 finding this fruit on two other species of this large genus, namely 

 diaphanum and strictum. 



In Cer. diaphanum the appearance with a power of 50 is both 

 peculiar and attractive. Instead of the crisp borders and deeply 

 coloured granules of the swollen joints as ordinarily seen the 

 colour is softened down, and the fluffy borders suggest an interposed 

 soft layer of semi-translucent substance only half concealing the 



