On the Pithophorace^e. 



79 



Fig. 13. The lower part of a fertile specimen with a rudimentary and very small 

 rhizo'id, rh. 



» 14. The lowest part of a fertile specimen with a rudimentary rhizo'id, rh, 

 divided from the cauloid by an incomplete parting-wall, w. The lowest cell of 

 the cauloid has formed a basal spore, sgb, which does also comprise the rudi- 

 mentary rhizo'id. 



» 15. The lowest part of a fertile specimen with a very short rhizo'id of one 

 cell, rh. The lowest cell of the cauloid has formed two spores, one apical, s, 

 and one basal, sgb. 



» 16. The lower part of a small fertile specimen with a rhizo'id of one cell and 

 of normal size. The top cell in the principal filament of the cauloid has for- 

 med first two branches, b, and then a terminal spore, st. 



» 17. The lowest part of a fertile specimen with a rather long rhizo'id of one 

 cell, rh. 



» 18. The lower part of a fertile specimen with a sporiferous rhizo'id of several 

 cells. The cauloid incloses among other things a prolific cell, p. 



P. polymorpha nob. 

 Fig. 19. The lower part of a fertile specimen with a sporiferous rhizo'id of several 

 cells, rh. 



PLATE V. 



All the figures are magnified 50 times. 



Figs. 1 to 8. Pithophora Cleveana nob. 

 Fig. 1. The lower part of a sterile specimen with an irregularly developed basal 

 part. The mother spore of the specimen has probably comprised the round 

 body, marked sg, and sent forth the three filaments of the rhizo'id, rh, down- 

 wards, h and h' are two unbranched helicoids. h forms the top of an accessorial 

 branch which is, against the rule, directed upwards. The case is the same 

 with the accessorial branch marked ad. 



» 2. The lower part of a fertile specimen with an irregularly developed basal 

 part, sg is probably the mother spore of the specimen, with two rhizo'id appen- 

 dices, rh. p is a prolific cell and h a helicoid. ac are accessorial branches 

 placed in a not very common manner. 



» 3. The lowest part of a fertile specimen without a rhizo'id. The basal cell of 

 the cauloid carries a helicoid, h, pointing downwards. 



» 4. A piece of the cauloid of a fertile specimen. The upper branch carries a 

 bifurcated helicoid, h. 



» 5. The top of a fertile branch with a trifurcated helicoid, 



» 6. The lower part of a fertile specimen with a rudimentary rhizo'id, rh, and 

 with a basal spore, sgb, and with a handlike three-fingered helicoid, h. 



» 7. The top of a fertile branch with a handlike helicoid, h. 



» 8. The top of a fertile branch with a terminal irregularly formed spore, hs, 

 which has probably originated in the transformation of a helicoi'd. 



