188 BRITISH SEA-WEEDS. {lUiodos^^ermece, 



Hab. On rocks and stones and shells, in deep water. 

 Annual. Summer. Rare. Mrs. GrilTiths, Torquay ; Mrs. 

 Wyatt, Salcombe; Eev. W. S. Hore, Plymouth; Mr. W. 

 Thompson, Portaferry ; Rev. J. H. Pollexfen, Orkney ; 

 D. L., in Lamia sh Bay, Arran. 



Seirospora Griffithsiana was formerly CaUUhammon seiro- 

 spermum, Griffiths. It was discovered by Mrs. Griffiths in 

 the autumn of 1833. It has, however, been found to differ 

 so much in fruit from CaUUhamnion as to lead Professor 

 Harvey to form a new genus for its reception. In Calli- 

 thamnion the tetrasporal fruit is borne laterally along the 

 branchlets : in this the tops of the branchlets are converted 

 into tetraspores. It is from one to three inches in height ; 

 colour a fine rosy-red ; substance soft, gelatinous, adhering 

 well to paper. It was found by us while dredging in Lam- 

 lash Loch, growing on living specimens of Pecten opercu- 

 laris.'^ It has been dredged by Major Martin on the 



* Our boatmen were surprised at the avidity vdih. which we grasped at 

 whatever was growing upon the scallops. Among other things there were 

 beautiful specimens of PInmularia CatJterina and PJumularia pinnata, zoo- 

 phytes which had certainly nothing in their appearance to recommend them 

 in their state of collapse when removed from their native element. Taking 

 one of the finest fronds of P. finnata, I dipped it in water, and told them to 

 look at it now. It had spread out into an elegant white plume ; and re- 



