Box.— Vol. I.] SAUNDERS— PHYCOLOGTCAL MEMOIRS. 1 63 



41. Scytosiphon lomentarius {Lyngb.) J. Ag. 



Plate XXXI, Figs. S-io. 



Scytosiphon lomentarius (Lyngb.), J. Ag., 1. c, 126. 

 Chorda lomentaria Lyngb., Hydrophyt. Dan., 74, 1819. 



Plant body unbranched, tubular, arising from short (i cm. long) filiform 

 stalks, 1-4 dm. long, i-io mm. thick; constrictions regular and frequent, 

 occurring at long intervals or entirely wanting. 



On rocks, Pacific Grove, Monterey, Santa Cruz, San 

 Pedro and San Diego, California (Averill's set). 



One form found mostly below the low tide line is broad 

 and short and the constrictions are regular and frequent ; 

 another form occurring on overhanging rocks at or above 

 the high tide line approaches the variety comflanatiis of 

 Rosenvinge. It is longer and more slender than the pre- 

 ceding form and the constrictions are seldom present. 

 Between these two there is such an imperceptible gradation 

 that it is difficult to draw a fine of separation. 



42. Scytosiphon bullosus, sp. nov. 

 Plate XXXI, Figs. 1-7. 



Plant erect, membranaceous, hollow, dark olive-green, cylindrical to 

 broadly ovate, 1-5 cm. high, 1-2 cm. broad, simple or lobed above, nar- 

 rowed at base into a broad disk-like attachment ; surface at first smooth, 

 wrinkled, and often torn with age. Plurilocular sporangia, paraphyses, and 

 hairs undistinguishable from those of S. lomentarius. 



On rocks, exposed at low tide with Lcathesia and Ulva. 

 Pacific Grove, California, Aug., 1896. 



A very variable species but apparently quite distinct from 

 S. lomentarius. 



43. Colpomenia Derh. & Sol. 



Colpomenia Derb. 6- Sol., Phys. Alg., p. 11, 1856. 



Plant body globose or oval, hollow, the walls entire or irregularly torn, 

 composed of two layers of tissue ; the inner layer consisting of a few large, 

 rounded, colorless cells, the outer of small quadrangular colored cells. Pluri- 

 lociilar sporangia at first forming sori around the hairs, soon spreadmg 

 over the whole surface of the plant, interspersed with unilocular, clavate, 



paraphyses. 



^ fa] Oct. 31, 1898. 



