IV. ECTOCARPACE^.— Cladostepiius. 135 



1. Cladostephus verticillatiis, Ag. ; branches slender, ramuli mostly forked, regu- 

 larly whorled ; the whorls at short intervals. J. Ag. Sp. Alg. 1, p. 43. Harv. 

 Pliyc. Br. t. 33. CI. Myriophjllum, Ag. Kiltz. Sp. Alg. p. 468. Conferva verticU- 

 lata, E. Bot. t. 1 71 8, and t. 2427,/. 2. (Tab. XI. C.) 



Hab. On tidal rocks, in pools near low water mark. Perennial. Newport, R. I. , 

 Mr. Olney and Prof. Bailey. Lynn, Mass., Mr. Hooper, (v. v.) 



Fronds 3 — 6 or 8 inches high, irregularly dichotomous, innovations springing 

 here and there along the principal divisions. Occasionally a large tuft of such 

 irregular branches issues from a single incrassated portion of the main stem, and is 

 either simple or forked. The whorls of ramuli are about a line asunder, the apices 

 of the lower whorl lying over the bases of that next above ; each ramulus is in- 

 curved, tapering to the base, and acute at the extremity, and bears above its 

 middle one or two subulate processes on the outer margin. The articulations are 

 shorter than their diameter, and longitudinally striate, each stria composed of 

 numerous seriated cellules. The fructification is formed in winter, at which season 

 most of the verticillate ramuli fall away, and their place is supplied by short, 

 densely set, accessory ramuli which bear the spores. These have been described by 

 authors as a parasitical Sphacelaria, and the name S. Bertiana bestowed on them. 



Plate XI. C. Fig. 1, a frond of Cladostephus verticillatus, the natural size; 

 fg. 2, small portion of a branch, magnified ; fig. 3, two of the whorled ramuli, 

 highly magnified. 



2. Cladostephus spongiosus, Ag. ; branchesthick and clumsy ; ramulimostly simple, 

 irregularly whorled, densely imbricated. J. Ag. Sp. Alg. I, p. 43. KUtz. Sp. Alg. 

 p. 469. Ifarv. Phyc. Brit. t. 138. Conferva spongiosa, E. Bot. t. 2427- / 1- 



Hab. On tidal rocks, at about half tide level. Perennial. With the preceding, 

 Mr. Olney. (v. v.). 



Smaller than the preceding, with thicker and more clumsy branches, and longer 

 and denser ramuli. I am not certain that the American specimens above quoted 

 have been rightly named, or are anything more than a variety of C. verticillatus. 

 The British plant looks something different ; but the technical characters by which 

 it is known are not always constant. 



