95 



absence of detailed information conceming the development of the 

 discoid holdfasts in the forms possessing them, Ieaves the opinion 

 that they result from reduction the more safe. Even in such a hi- 

 ghly developed form as Egregia, perhaps the highest expression of 

 development within the family, there results in certain environments 

 a huge disk which does not at ali represent the primitive disk, but 

 which comes from the expansion of the haptere-forming tissucs of 

 the lowermost portion of the stipe in a fashion similar to that in 

 which the bulb is formed in Saccarinati bulbosa. In Cymathaere and 

 in L. ephemera, it certainly seems to be the case that the discoid 

 holdfast represents more than a hypcrtrophied primitive disk, that 

 it includes growth also from the rhizogen as vvell, and it is my be- 

 lief that this vvill be found to be true also of L. solidungula and of 

 L. ye\7joensis, as it certainly is of the bulbous and discoid expansions 

 in Saccorhi^a bulbosa and both species of Egregia. 



Pterygophora Cai/fornica Ruprecht is a species common on ex- 

 posed shores along the western coasts of North America from the 

 region of Puget Sound on the North to San Diego, California, on 

 the South. It may usually be found in the proper localities, just be- 

 low low water mark, on the more or less exposcd rocks, raising its 

 bunch of long sporophylls above the surface of the water at extreme 

 low tide. It descends into depths of two to five fathoms and perhaps 

 deeper and along the southernmost portions of its range seems to 

 prefer the deeper water. It is often cast ashore in very considerable 

 quantities and besides being the support of numerous smaller epi- 

 phytes of ali sorts, it often has one to several plants of Nereocystis 

 Luelheana attached to its stipe when it grows in the deeper water. 

 This plant was first described and figured by Ruprecht (Bemerk. 

 ueb. d. Bau. u. d. Wachsthum einiger grossen Algcn-Stàmme, p. 64, 

 1848 and Neue oder unvollst. bekannte Pflanzen a. d. nòrdl. Th. d. 

 Stillen Oceans, p. 17, pi. 5 and 8, i852), but his plants were ali 

 young, and, as his figures seem plainly to show, he failed to notice 

 the method of origin of the sporophylls and cause it to be repre- 

 sented on the piate of the habit of his plants. Areschoug, also, had 

 only young specimens (Obs. Phyc, pt. 5, p. 11, 1884) and conse- 

 quently added little to our knowledge of the gross morphology. I 

 was the first to cali attention to the mode of origin of the sporo- 



