102 University of California Pvhlicatians in Botany [Vol. 8 



Growing iu rock depressions of the breakwater, San Pedro, Cali- 

 fornia. This is the only known locality on the Pacific Coast of North 

 America. 



Harvey, Ner. Bor.-Amer. Ill, 1858, p. 106 ; Bornet and Flaliault, 

 Rev. I, 1886, p. 362; Collins, Holden and Setchell, Phyc. Bor.-Amer. 

 (Exsicc), no. 2105. 



The only specimen we have found sufficiently characteristic to 

 refer confidently to this species has been compared with a fragment 

 of the type specimen from Sakonnet Point, Rhode Island. The two 

 agree very well indeed, except that our specimen shows more abundant 

 and seemingly more characteristic branching. 



12. Calothrix pilosa Harv. 



Plate 8, fig. 4 



Filaments forming a widely expanded, caespitose, pilose, dark blue- 

 green stratum, decumbent, and densely interwoven at the base, both 

 ends erect above, elongate, rigid, 2-10 mm. high. 10-40/a thick ; sheaths 

 firm, thick, golden, at times yellowish brown, subopaque, homogeneous ; 

 trichomes 10-20/a diam., olive brown to pale blue-green, briefly attenu- 

 ated above; heterocysts basal and intercalary. 



Forming a dense velvety coating on rocks in tide pools along 

 high-tide level, or often above. Point Carmel, in the vicinity of 

 Carmel Bay, California. 



Harvej', Ner. Bor.-Amer. Ill, 1858, p. 106, pi. 48c; Bornet and 

 Flahault, Rev. I, 1886, p. 363; Collins, Holden and Setchell, Phyc. 

 Bor.-Amer. (Exsicc), no. 859. 



The plants referred here were all found in a single locality, viz., 

 Point Carmel in Monterey County, California, but were collected in 

 different years and months and independently by each of us. They 

 form velvety linings to minute pools high up in the littoral region 

 where the water is much warmed and concentrated by the sun. It 

 is usual to find salt crystals in these pools, to such an extent has the 

 evaporation proceeded. Harvey describes and figures the branches 

 as single and after the fashion of C. prolifera, and his figures agree 

 in all respects with a fragment of the tj^pe of C. pilosa. Certain of 

 our specimens show the same method. Others with decumbent base 

 show branching similar to C. fa^ciculata, and still others with the same 

 sort of base show the branching of C. vivipara. 



