T. H. BUFFHAM ON SOME FLORIDE^. 189 



sporic the sporangia which approached maturity contained 

 more than four spores. After immersion in either glycerine, 

 or a saturated solution of sodium chloride, the appearance is 

 like that of Fig. 17 6, where five or six spores are readily seen 

 with a confused centre of the group. This central part appears 

 to be the end of one or two other spores. The nearly mature 

 sporangia are ellipsoidal, about 65 //. long and 55 \x thick. Even 

 when much smaller the divisions can generally be traced (Fig. 

 17a), but frequently the earlier stages assume the normal pre- 

 sentation of a tetrasporangium of the typical tripartite character. 

 A scrutiny of the larger of these will, however, generally show a 

 trace of the further division of each quarter visible, so that I 

 am led to doubt the existence of true tetraspores in this species, 

 and to regard the sporangia as octosporangia, and the production 

 of eight spores as normal. (Torpoint, September, 1895). 



In Ptilota plumosa Ag. some tetraspores have been seen on 

 the same plant with procarps ; and the involucre of an old 

 cystocarp (or possibly of an unfecun dated procarp) became 

 branched near the tips, and developed tetrasporangia. 



Explanation of Plate X. 



Fig. 1. Chondrus crispus Stackh. Portion of plant with 



antheridia, natural size. 

 „ 2. Ditto. Transverse section of unchanged portion of 



thallus x 400. 

 ,, 3. Ditto. Vertical section of antheridial layer x 400. 

 „ 4. Gigartina mamillosa J. Ag. Three branches bearing 



antheridia, natural size. 

 ,. 5. Ditto. Surface view of circular antheridial spot 



x 50. 

 „ 6. Ditto. Antheridia seen near the edge of thallus 



x 200. 

 ,, 7. Ditto. Surface view of tangential section of anthe- 

 ridial layer x 400. 

 „ 8. Ditto. Vertical section of antheridial layer x 400. 

 ,, 9. Ghylocladia ovalis Hook. Antheridial patches on 



branchlet x 20. 

 „ 10. Ditto. Surface view of portion x 50. 

 „ 11. Ditto. Vertical section x 400. 



