136 
ECT0CARPACE2E. — Cil^tofte'eis. — S pit acel aria. 
IY. 
II. CELETOPTERIS. Kiitz. 
Frond filiform, compressed, inarticulate, distichously pinnate. Stem cellular, 
omposed of a triple stratification of cellules ; the central portion of longitudinal, 
prismatic cells, horizontally connected ; the intermediate of roundish cells ; the 
outer of minute cellules. Fructification: — spores (unknown). The sphacelate tips 
of the pinnated ramuli contain a sporaceous mass or propagulum. 
This genus has the habit of Sjohacelaria, with which it has until recently been 
associated by authors, and a structure of stem similar to that of Claclostephus. It 
is therefore exactly intermediate between these genera. 
1. Chaetopteris plumosa, Kiitz. ; stems naked at the base, elongated, irregularly 
branched ; branches pectinato-pinnate ; pinnae opposite, simple, very long, closely 
set. Kiitz. Sp. Alg. p. 468. J. Ag. Sp. Alg. 1. p. 41. Sphacelaria plumosa, Ag. 
Haw. Pliyc. Brit. t. 87. Conferva pinnata, E. Bot. t. 2330, ( left hand fig.) 
Hab. On the shores of Greenland, J. Agardh. Arctic Coast, Mr. Seeman. (v. v.) 
Fronds from two to four or six inches long, setaceous, naked below, irregularly 
and much branched above. Branches alternate or secund, or frequently tufted, one 
or two inches long, simple, closely pectinated along their whole length with slender, 
articulated, distichous ramuli. These ramuli are from one to three lines long, oppo- 
site, a pair growing from every joint of the branch. 
This beautiful plant is peculiarly a northern form, and though it reaches the south 
of England, is there of much smaller size than on the shores of Scotland. The 
branches resemble delicate feathers, 
III. SPHACELARIA. Lyngb. 
Frond filiform, articulated, distichously branched, rigid, pinnated, rarely subdicho* 
tomous. Articulations of the stem and larger branches composed of several cells 
radiating from a central point. Apices of the branches distended, membranous, 
containing a sporaceous mass or propagidum. Spores ovoid, having a pellucid 
perispore , affixed to the branches. 
