278 Puget Sound Marine Sta. Pub. Vol. 1, No. 25 



thin^ with a distinct midrib; sporophylls on both sides of the rachis, long 

 or short, broad or narrow, of definite growth; sorus almost covering both 

 surfaces of the mature sporophyll. 



The species of Alaria in this vicinity are in need of further study 

 in order to straighten out some of the difficulties confronted in determin- 

 ing the species. The length and width of stipe, blade, midrib and sporo- 

 phylls have been used as the basis for separating several so-called species. 

 The occurrence of so many intermediate stages or forms compared with 

 the few specimens that really answer the specific descriptions have led 

 the writer to include our specimens of Alaria at least for the present, 

 in two species, A. tenuifolia and A. valida. 



KEY TO SPKCIES 



A. Stipe much flattened. 1. A. tenuifolia 



AA. Stipe cylindrical or flattened only above. 2. A. valida 



\. Alaria tenuifolia Setchell in Collins, Holden & Setchell, P. B. A. 



Fig. 43 



Holdfast composed of numerous branching hapteres ; stipe five to 

 eight dm. long, terete only at the very base, the rest much flattened, slen- 

 der, flexible. Blade from one to four meters long, twenty-five to thirty- 

 five cm. or more wide, very thin ; midrib eight to twelve mm. wide ; sporo- 

 phylls when mature short and broad, cordate at the base, with rather dis- 

 tinct stalks, in pairs on the flattened more or less elongated rachis. 



A variable species represented by several forms. Common on the 

 boulders and stones in the upper sublittoral zone. 



2. Alaria valida Kjellman & Setchell, in Setchell & Gardner's Algae of 

 N. W. Am. p. 278, pi. 21. Fig. 44 



Holdfast similar to the above species; stipe three to forty cm. long, 

 terete or flattened only above, firm; blade two to five meters long, oblong- 

 lanceolate, tapering below, somewhat undulate, plicate; midrib five to 

 twenty mm. wide; sporophylls broad or sometimes narrow, varying in 

 length from ten to forty cm., tip often pointed, base often cordate, with 

 short stalks; sorus almost covering the sporophyll except for a margin 

 around the outer edge. 



Upper sublittoral zone, sometimes in the lower littoral zone. 



Under the above species the writer has included Alaria cordata 

 Tilden, Am. Algae 241, and Alaria valida Kjellman and Setchell. 



So far the writer has been unable to find any. of the characteristics 

 that are supposed to separate these two species to hold constant under 

 different conditions. According to Setchell (14) p. 278 and pi. 21, the 



