vol.i] SeMiell-Gardner. — Algce of Northwestern America. 215 



L. M. Turner, No. 849 (Herb. U. S. National Museum) ! , W.A.8., 

 Nos. 5235!, 5243x!, and in Collins, Holden and Setehell, 

 -P. B.-A., No. 969!, under Hormidium parietinum; St. Paul 

 Island, Alaska. B. W. Everman ! (Setehell, 1889, p. 590) ; Iliuliuk, 

 Unalaska, Alaska, W.A.S. and A.A.L., No. 4010!; St. Paul, 

 Kadiak Island, Alaska, W.A.S. and A.A.L., No. 5137! ,-8aunders 

 (1901, p. 412, under Hormidium parietinum); Orca, Alaska, 

 W.A.S. and A.A.L.. Nos. 5182!, 5183! ; Takutat Bay, Alaska, 

 Saunders (1901, p. 412); Juneau, Alaska, TT.A.S. and A.A.L., 

 Nos. 5191!. 5192!; Departure Bay, Vancouver Island, B. C, 

 W.A.S. and A.A.L., No. 5211!; Coupeville, Whidbey Island, 

 Wash.. X.L.G.. 669! 



The specimens quoted above include all sorts of conditions 

 from the typical P. crispa with its broad flat frond, to filamen- 

 tous forms referable to Hormidium parietinum (Vaucher) Kuetz- 

 ing or even to H. murale (Lyngbye) Kuetzing. In the majority of 

 cases, these forms are mixed in the same collection and often show 

 more or less perfect transitions from the one to the other. 



Prasiola calophylla (Carmichael) Meneghini. 



In brackish water at the head of Penn's Cove, Whidbey 

 Island. Wash.. X.L.G.. No. 258! 



This narrow species contrasts very decidedly with P. crispa, 

 as well as with the next two species in the shape of the frond and 

 the arrangement of the cells. We have been unable to compare 

 it with authentic specimens but it answers to the descriptions and 

 the figures so exactly that we feel little doubt concerning it. 



Prasiola borealis Reed. 



On rocks, just above high water mark. Iliuliuk, Unalaska, 

 Alaska. W.A.S. and A.A.L., Nos. 4013!, 4021!; St. Paul, 

 Kadiak Island, Alaska, W.A.S. and A.A.L., No. 5138! 



This species comes nearest to P. Antarctica Kuetzing, but dif- 

 fers from it in shape and color of the fronds and in the less 

 regular tetrad arrangement of the cells. The specimens of P. 

 borealis are infested with a fungus (Guignardia Alaskana Reed) 

 just as the Antarctic species is with Guignardia Prasiola, 

 (Winter) Reed, which gave rise to the genera Mastodia Hooker 

 and Harvey and Dermafomeris Reinsch. For further details 



