116 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 26 



PLATE 5 



Antithamnion dend.roid.eum Sm. & Holl. A tetrasporangial branch, 

 X 340. 



Antithamnion hubbsii sp. nov. Part of a lower axis showing a rhizoid, 

 X 206. 



Antithamnion breviramosus var. simplex Daws. A sterile axis, X 65. 



Antithamnion mcnabbii Daws. Part of a mature axis showing only 

 one of three whorled, lateral, determinate branches at a node, X 305. 



Fig. 5. Antithamnion Iherminiteri (Cr. & Cr.) Nasr. Habit, X 100. 



