vol. i] Setchell— Gardner. — Alga of Northwestern America . 24 1 



Cross sections of the larger branches show a structure inter- 

 mediate between that of the two species mentioned. The J). 

 intermedia P. & R. seems to be made up of this form as Agardh 

 pictures it and other forms of D. aculeata. Postels and Knprecht 

 ( 1S40, p. 13) mention a variety teretifolia as occuring at Sitka 

 and another variety, fuscescens, as occurring on the Alaskan 

 Peninsula. The former seems likely to be the same as our plant, 

 but the latter is less likely to be placed here ; probably to be placed 

 rather with the type of D. aculeata. Kuetziug's figures (1859, 

 pi. 96) of D. intermedia are evidently not of this form, nor is the 

 D. media of the same author (loc. cit., pi. 95) , but the D. hybrida 

 (loe. cit.. pi. 93) may possibly be. The f. media certainly needs 

 more study and particularly the young plants, none of which are 

 available to us. 



Desmarestia ligulata (Lightfoot) Lamouroux. 



In ten fathoms of water. Burrard's Inlet, B. C, Harvey 

 (1862. p. 164). 



Harvey says that the type and var. herbacea were found in 

 the same locality. Very few, if any, of frhe plauts which we have 

 been able to examine correspond to the slender form from Euro- 

 pean localities which may more properly stand for the type, but 

 are to be counted under the following form. The variation of 

 width in this species and the distinctness of the veining, is very 

 great, at least as far as the plants of the Pacific Coast of North 

 America are concerned. 



Desmarestia ligulata f. herbacea (Turner) J. Agardh. 



Northwest coast of Xorth America, Turner (1809, p. 77, pi. 

 99, under Fucus herbaceus) ; Norfolk Sound (near Sitka), Alaska, 

 Postels and Buprecht (1840, p. 13, under Besmia herbacea) ; Bur- 

 rarcl Inlet. B. C, Harvey (1862, p. 164); Oak Bay, Victoria, B. 

 C Tilden, No. 244!; Port Renfrew, B. C, Butler and Volley, 

 No. 7: west coast of Whidbey Island. Wash., X.L.G., Nos. 85!, 

 120! 



This form is plentiful in the region of Puget Sound, but is ap- 

 parently rarer to the northward. It varies very much in width. 

 One of us (W.A.S.) has noted it at Esquimalt, B. C, cast ashore 

 in fragments several meters long and full 30 centimeters wide. 



