292 THE SEA-WEEDS AT HOME AND ABROAD. 
Americana, dedicated to Henry Grinnell of New York, in 
honor of his noble conduct in an expedition fitted out by him 
in search of Sir John Franklin, and known to American bota- 
nists as the Grinellia of Professor Harvey. In Nitophyllum 
we have a ribless frond, traversed by slender irregular 
veins; the frond broad membranous and variously divided, 
= hoses in the form of dots deep in the pulp of the leaf. 
blepharis ciliata has the margins of its rich dark red 
Fus beautifully ciliated or fringed; Botryoglossum and 
Hymenena are California species and can scarcely be looked 
for with any degree of success hereabouts. The Rhodo- 
menie, with Huthora, are plants of great beauty, and need 
scarcely more than be named as the species are few; R. pal- 
mata is parasitic on alge in shallow water; R. palmetta on 
the larger kinds in deeper soundings, and Z. cristata extends 
in its range from the Arctic coast to Cape Cod. 
Among the most abundant of these rosy-seeded alge, and 
likewise of the most delicate structure, we notice the Cera- 
miacee, with fronds growing in close tufts, but sometimes 
‘solitary, creeping along the surface by fibres or affixed by 
disks, the stems slender, thread-like, articulated, dichoto- 
mously or pinnately branched, and sometimes growing so 
interwoven as to form network or spongy masses. In some 
species the space between the joints is diaphanous, which 
gives a strikingly beautiful appearance; in others the joints 
exhibit no such peculiarity. The species are exceedingly 
numerous, and the search for rarer ones in any given district 
would be compensating to him who does not despise trifles 
such as these at first seem. 
The last of the Rhodosperms to which we invite your at- 
tention is Callithamnion, a very large genus of beautiful 
alge, mostly small and many even minute, the different spe- 
cies difficult of determination, subject as they are to constant 
variation. The elegance of their several parts in stem, 
branches, and branchlets, the delicacy of their subdivisions, 
their exquisite color and the symmetry of the seed-vessels 
