1925] Setchell-Gardner : 3Iehinophyceae 563 



and surrounded in turn by the cortex of colored, radially elongated 

 cells ; reproduction and hairs unknown. 



Cast ashore. Argyle, San Juan County, Washington. 



Setchell and Gardner, Phyc. Cont., VII, 1924, p. 7. 



We have but two portions of what may be a single ample plant of 

 this sjiecies upon which to base this description. The character of the 

 holdfast and of the lower parts of the frond cannot be chronicled at 

 this time, but the characters of the parts which we have are so pro- 

 nounced as to leave little doubt that the species has hitherto been 

 overlooked and is undescribed. One of the incomplete specimens, 

 probably a portion of the same plant, is in the collection of the Marine 

 Biological Station at Friday Harbor, Washington, and we are able 

 to examine it through the courtesy of Professor T. C. Frye. The 

 densely "stuifed" condition of the cells of the central monosiphonous 

 axis begins within two or three cells of the tip of each axis through 

 the growth of tylloses, a condition not noted by us in any other of the 

 specimens available to us. 



Section 2. Aculeatae 

 Desmarestia, subgen. Eudesmarestia DeToni. 



Fronds compressed to slightly flattened, never strictly flattened- 

 foliaceous, f oliaceous, or cylindrical ; branching alternate, occasionally 

 opposite below. 



DeToni, Syll. Alg., vol. 3, 1895, p. 457 (in part). 



4. Desmarestia latifrons (Rupr.) Kuetz. 

 Plate 90 



Fronds of a firm, rigid consistency, dark brown in color, moderately 

 branched, flattened throughout except the base of the stipe, several 

 main lateral branches often exceeding in length the central axis, 

 midrib manifest only in the lower older parts, 8-15 dm. high, 2-3 mm. 

 wide ; branches of 3-4 orders, those of the fourth order f oliaceous 

 above, reduced to small aculeae below or entirely absent ; hairs oppo- 

 site, branched, arising from every cell of the central axial filament, 

 closely congested along the entire margin of the corticated frond and 

 of the ramuli except at their stipitate bases. 



Growing on rocks in the lower littoral and the upper sublittoral 

 belts. Central Oregon (Coos Bay) to central California (Point Sur). 



