318 ALLAX HANCOCK PACIFIC EXPEDITIONS VOL. 12 



PLATE 1 



Figs. 1, 2. Roodlea composita, f. Fig. 1, a small portion of a thalius 

 to show its characteristics in the plane phase, x 15. Fig. 

 2, tip of a hranchlet showing a hapteral cell attaching 

 to a larger segment, x 73. Ecuador. 



Figs. 3-6. Derhrsia lont/ifructa. Four oval-oblong sporangia at- 

 tached to the supporting filaments, showing the basal 

 septum or, in fig. 3, a definite stalk cell. Ecuador, x 115. 



Figs. 7-9. Derhcsia Hollcnherc/ii. Portions of three filaments to 

 show \oung subturbinate sporangia, and an old spo- 

 rangium with an evident stalk cell. I. Santa Maria, x 70. 



Figs. 10-13. Codium isabclac. Four peripheral utricles, each showing 

 a much-thickened end ^vall and one or two gametangia. 

 I. Isabela. x 70. 



Figs. 14-16. Codium santainariae. Three peripheral utricles with 

 slightly thickened end walls and solitaria gametangia. 

 I. Santa Maria, x 70. 



Figs. 17-18. Acetabiilaria parviila v. americana. Fig. 17, one seg- 

 ment of a disk and portions of others, to sho\v the un- 

 armed end wall, x 90. Fig. 18, insert, two coronal proc- 

 esses to show the hair scars, x 140. Is. Revilla Gigedo. 



