Alga.} CALIFORNIA.— SUPPLEMENT. 409 



2. G. lanceolatum, Harv. supra, p. 164. 



Monterrey, Douglas. 



1. Gigartina canaliculata (Harv.) ; fronde erecta compressa canaliculata basi simplici, 

 apice creberrime bipinnata, pinnulis patentibus subulatis vel multifidis, ramulis aculei- 

 formibus, capsulis inter aculeos sessilibus. — Gelidium corniculatum, Harv. supra, p. 164. 

 (not of Grev.) 



Root accompanied by creeping fibres. Stem erect, 2-3 inches high, a line broad, compressed, channelled 

 on one side, linear, simple or once or twice forked, and bare of ramuli for three-fourths of its length ; thence 

 upwards it is pinnated, or in old specimens bipinnated, the pinnae and pinnules alternate, horizontal, subulate, 

 very acute ; the pinnulse in some specimens simple, in others cleft at the apex into 3-5 or more divaricating 

 spine-like ramuli. Capsules minute, depressed in the centre, of the same substance and colour as the frond, 

 seated on the multifid pinnules. Substance cartilaginous. Colour a dull purple, paler in the ramuli, becoming 

 much darker in drying. — In a young state this species bears a striking resemblance to Turner's figure of 

 Fucus corniculatus, t. 182, and at p. 164 of the present work I have noticed it as such. But more perfect 

 specimens, since received, prove that it is perfectly distinct from that and every other described species. The 

 channelled stem, naked for its greater length, and the dense head of multifid spine-like ramuli sufficiently mark 

 the species. 



San Francisco, Mr Douglas. 



2. G. muricata (Harv.) ; pusilla, fronde filiformi cartilaginea subdichotoma spinulis 

 minutissimis acutis muricata, apicibus divaricatis acutis, capsulis spbaericis sessilibus. 



An inch high, densely tufted, cylindrical, irregularly divided in a subdichotomous manner, the upper 

 divisions patent, the whole frond rough with minute thorns. Capsules large, spliEerical, solitary on the 

 ramuli. Colour a deep purple. 



San Francisco, Dr Sinclair. 



Tbibe 4. GASTROCARPE.E. 



1. Iridaea papillata, Grev — Spbasrococcus papillatus, Ag.p. 222. — Harv. supra, p. 165. 

 San Francisco, Dr Sinclair. Monterrey, Douglas. 



2. I. Radula, Grev. — Fucus bracteatus, Turn. Hist. t. 25. 

 San Francisco, Dr Sinclair. Monterrey, Douglas.' 



3. I. stiriata, Grev. — Fucus stiriatus, Turn. Hist. t. 16. 



Tribe 5. ULVACEjE. 



1. Porphyra vulgaris, Ag. 



San Francisco, Dr Sinclair. 



1. Diatoma obliquatum, Ag. — Conferva obliquata, Eng. Bot. t. 1869. 



Parasitical on Stenogramma Californicum, on which plant I also perceived a specimen of that curious 

 minute genus of Zoophytes, Actinocyclis. 



3 F 



