ON SOME NEWLY-FOUND ANTHERIDIA. 341 



Call, byssoideum is a very interesting plant on account of the 

 excessive tenuity of its ramuli, although the plant itself is from 2 to 

 4 inches in height. In Fig. 4 a minute portion of a branch is drawn 

 as seen with a power of 40. The apical part of one of the fila- 

 ments there shewn is drawn at Fig. 5 as seen with -^ inch x 600. It 

 bears three antheridia which are the most delicate objects of this 

 kind I have ever seen. They are quite hyaline, with the exception 

 of the cellules forming the axis. The antherozoids are very elon- 

 gated, and their attachment can scarcely be made out in the only 

 specimen I have yet seen, which was taken at Dartmouth last 

 August. 



Our next is a very different plant — Call. Twneri. The height 

 of the specimen is scarcely ^ inch, and of this fig. 6 shows only 

 the upper portion as seen with \ inch x 200. Here the antheridia 

 cluster thickly on the ramuli. Some are seen arising from ramuli 

 behind the anterior ones. They are of various stages of develop- 

 ment ; of ellipsoidal form, not quite regular ; colourless, and filled 

 with antherozoids. I found this thickly investing a larger alga at 

 Brighton in July, 1882. 



In April of the same year I took at Folkestone Call, roseum 

 with antheridia. These are globose when near maturity, but are so 

 thickly placed on the ramuli in the position usually occupied by the 

 tetraspores, that as they become older they almost coalesce, so as to 

 form a continuous band. Their general appearance is very similar 

 to that of Call, polyspermum figured in " Phycologia Britannica." 



The last example of antheridia in this beautiful genus that I have 

 to describe is one that Harvey truly designates "a charming plant," 

 which we will continue for the present to call Call. Plumula, 

 although it has been given various other generic names on the 

 continent. In my specimen the ramuli are very close, and from 

 these branch out numerous compound ramuli. In PI. XI. Fig 1, one 

 of the ramuli is shown having three antheridia on it x 80. In Fig. 

 2 the same three antheridia are drawn as seen with -^ inch x 1,000, 

 and in various stages of development, the largest being, of course 

 the most mature. The pedicel is prolonged into the antheridium, 

 and is branched and sub-divided several times, the antheridium 

 becoming, in fact, a lovely little shrub, — if such a term be allowable 

 for an object measuring about -001 inch in height. They are found 

 on the compound ramuli as well. Although drawn as simply 

 as possible to render their structure more comprehensible they 



