SIPHONACE^. 29 



] . CoDiuM tomentosum, Stack. ; frond linear, dichotomous, cylindrical or compressed. 

 Ag. Sp. Alg. \.p. 542. Wyatt, Alg. Damn. No. 35. Kutz. Sp. Alg.p. 500. Harv. 

 Phyc. Brit. t. 93. Fucus tomentosus, E. Bot ^.712. Turn. Hist. t. 135. 



Hab. Apalachicola, Captain Pike. Manatee River, Mr. Ashmead. Key "West, 

 W. H. H. Sitcha, Ruprecht. California, Dr. Coulter. (Not received from the east 

 coast), (v.v.) 



Fronds rising from an expanded, velvetty incrustation, solitary, or gregarious, from 

 three inches to one or two feet in length, varying much in diameter, erect, dichotomous, 

 with or without lateral accessory branches. Branches cylindrical or compressed, ob- 

 tuse, clothed with hyaline, spreading, soft, byssoid hairs, which, when the plant is ex- 

 panded in water, stand out vertically on all sides, and give to the branches the tomentose 

 character commemorated in the trivial name. The axis is composed of innumerable, 

 interwoven, irregularly branched, slender filaments, from whose sides issue radiating, 

 horizontal, clubshaped ramuli, whose apices, closely placed, but not cohering, form 

 the surface of the spongy frond. To the sides of these ramuli are attached the spo- 

 rangia, which are oval or ovato-lanceolate, and subsessile. 



It is a singular fact, (if it be really a fact) that this well-known and common species, 

 which is found in every latitude from the Equator to the colder parts of the temperate 

 zone, and nearly to the polar basin, is not a native of the Eastern coast of North Ame- 

 rica. It has not been sent to me by any of my correspondents from any part of the 

 Atlantic coast, except from Florida, at the mouth of the Mexican Gulf. There I have 

 myself gathered it. On the west coast it appears to be abundant, and extends as far 

 north as Sitcha. There is nothing to distinguish Californian specimens from those found 

 in Europe, in Ceylon, in Australia, at the Cape of Good Hope, or at Cape Horn, at all 

 which places it is common. 



V. CHLORODESMIS. Bail, and Harv. 



Frond pencil-form, stipitate or sub-sessile, flaccid, without calcareous incrustation, 

 wholly composed of cylindrical, dichotomous, unicellular filaments filled with dense, 

 vivid-green endochrome. Stipes, when present, spongy, formed of interwoven 

 threads. 



The genus Chlorodesmis was founded by the late lamented Professor Bailey and my- 

 self on an alga brought by Captain Wilkes from the Feejee Islands, and which I have 

 since collected abundantly on all the coral reefs which I had the opportunity of visiting 

 in the tropical Pacific, where it forms a very striking object on the extreme outer edge 

 of the reef. This original species — C. comosa, Bail, and Harv. — has a distinct, and 



