SERTULA1UA ARGENTEA. 269 



STEMS slightly waved, of a dark horn-colour, subspirally 

 branched; branches alternate, approximate, tiro to each 

 internode, panicled, dichotomously divided and subdivided, 

 so as to form somewhat broad fan-shaped offshoots, 

 springing from different sides of the stem, in such a 

 manner that four or five constitute a whorl ; HYDRO- 

 THEC.E subalternate, short, urceolate, narrowed toivards 

 the upper part, which is free and divergent, and produced 

 into an acute point at the outer side, aperture small 

 and oblique; GONOTHEC.E broad at the top, attenuated 

 downwards, with two spines above, or sometimes only 

 one, and a slightly raised, circular apertiire. 



ELLIS'S expressive name for this species, " the Squirrel's 

 tail," gives a better idea of its general aspect than any 

 technical description. The stems are thickly clothed with 

 branches to the very bottom ; but for some distance below 

 they are small, and they also diminish towards the apex, 

 the intermediate region being occupied by panicles of about 

 equal size, so arranged as to cover the stem completely 

 and produce the rotund and bushy appearance which is 

 characteristic of the species. The branches divide and 

 subdivide dichotomously ; and at certain seasons the pin- 

 nules thus formed bear the capsules, profusely, in rows. 



In its young state S. argentea is simply pinnate, and 

 the pinnae all lie in the same plane ; but the branches soon 

 begin to divide and assume the corkscrew arrangement. 



The shoots attain the height of a foot or more, and are 

 occasionally bifid ; they grow in dense clusters. 



Hab. On shells, stones, &c. chiefly from deep water; 

 generally distributed. One of the principal elements of 

 the trawl-refuse on the south-west coast. S. argentea also 

 occurs at times between tide-marks, but of small size. 



[Ostend (Van Ben.): mouth of the Elbe (Kirchenpauer) : 

 Greenland (Fabr. and Morch) : North Cape in 30-50 fath. 



