( SOS } 
XVIII.- — Description of Plumularia bullata, m 
new Species, collected by the Arctic Eoopeditioru 
under Capt. Parry, in Hudson's Straity\^%\^ 
By the Rev. John Fleming, D.D. F. R.S.iL 
M.W.S. &c.. . 
(Read mh March 1824.> 
TDhIS coralline * is irregularly branched. Each brancfe 
arises from a cell (or denticle), which has enlarged into aw 
ovate vesicle, slightly wrinkled across. From the top of 
this vesicle a tubular stem proceeds, thinly covered on one- 
side with a row of cells, some of which are enlarged into 
vesicles supporting other branches. The base of the vesicle 
is united with the mouth of the cell, but the line of sepa-. 
ration is distinct, in censequence of the cell (and branch 
with which it is connected) being of a denser substance* 
In the yovmger branches, the communication between the 
central tube of the stem and the cavity of the vesicle is 
free ; in the older portions, however, this connection ceasesi 
At the external base of the vesicle, from one to three tubu» 
lar radicles take their rise, and descend along the support- 
ing stem, and others which are inferior to it, closely adher« 
See Plate IXv 
