206 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 12 



the cortex which form a network and more refractive filaments which 

 anastomose sparingly and occasionally form an inconspicuous polyradiate 

 ganglionic structure, the cortex of an inner loose la3^er of colorless cells 

 attached to the medullary filaments and an outer layer of small cells, 

 rounded and 6-9 /j. diam. in surface view, separated in the peripheral 

 jelly by almost their own diameters; tetrasporangia scattered in the 

 cortex, tetrapartite, spherical to oval, about 9 ju, diam., to 15 ^ long. 



This species differs in thickness and absence of conspicuous ganglionic 

 cells from H. actinophysa Howe, in its relative thinness and inconspicuous 

 ganglioid cells from H. calif ornica Smith k Hollenberg (1943, p. 216, 

 figs. 18, 19). 



Ecuador: Archipielago de Colon, one plant dredged from 55 meters 

 off Post Office Bay, I. Santa Maria, no. 34-383 (tetrasporic, TYPE), 29 

 Jan. 1934. 



Halymenia utriana n. sp.^22 

 Plate 64, Fig. 2 



Plants small, to 12 cm tall, narrowly ligulate, simple or once forked, 

 the divisions erect, rounded at the tips, tapering gradually from a width 

 of 1.5 cm to the minute holdfast; texture soft membranous, color rose 

 red, thickness 35-100 fx; the cortex of one, occasionally two layers of 

 cells angular in surface view, 15-25 [x diam., and a medulla of anastomos- 

 ing filaments which appear to have soft coalescing walls in the younger 

 parts but below occupy about half the thickness of the blade, are looser 

 and the walls apparently thinner, not being associated with marked gang- 

 lionic fusions of filaments; cystocarps about 0.25 mm diam., swollen on 

 both sides of the blade, the carpospores forming a solid mass surrounded 

 by a thin medullary filamentous layer. 



Colombia: Choco, dredged in 37 meters' depth off Ba. Utria, no. 

 34-501 J (sterile and cystocarpic, TYPE), 14 Feb. 1934. 



Halymenia actinophysa Howe 



Howel911,p. 509, pi. 34. 



The arachnoid cells characteristic of this species are readily visible at 

 moderate magnifications through the cortex of the fresh or soaked speci- 

 men, even without staining, readily differentiating it from the other West 

 coast species. 



122 Hal3'menia utriana n. sp. — Plantae ad 12 cm altitudine, angustae ligulatae, 

 subsimplices, cacuminibus rotundatis, ab 1.5 cm ad hapteron minutum attenuantes; 

 molli-membranaceae, 35-100 n crassitudine; gangliis perspicuis absentibus, cellulls 

 corticeis superficiei 15-25 |x diam.; cystocarpis 0.25 mm diam., utrumque latus 

 laminae distendentibus. Planta typica in loco dicto Ba. Utria, Choco, Colombia, 

 legit W. R. Taylor no. 34-510 A, 14 Feb. 1934. 



