THE FLORA OF THE WORMS HEAD 89 



circumstances, and considering that the characters of each are 

 sufficiently distinctive, I would suggest that the most reasonable, 

 and probably the most correct, way out of the difficulty is to 

 establish a third genus for the reception of the Alga described as 

 " Polychatopliora simplex." I would suggest OligochcetojyJiora as 

 the name of this genus, and the following as a synopsis of the 

 three genera discussed above : — 



PoLYCHJETOPHORA W. & G. S. Wost, 1903. Freshwater. Not 

 known to be epiphytic. Cells subglobose, ellipsoid, or ovoid, 

 solitary or more usitally 2 to 6 aggregated to form a suhfilamentous 

 thallus ; cell-tvall very thick and strongly lamellose. Each cell 

 furnished with 8-12 long, flexuose, simple seta of a delicate 

 character and without a sheath, mostly arising from the sides of 

 the cells, hut also from the dorsal surface. Chloroplast single, 

 parietal, and often indistinct in its limitations. 



1. P. lamellosa W. & G. S. West. Diam. cell. 19-35 fx ; crass. 

 cell, membr. 2-8-10-5 /jl ; long. set. 86-183 /x. 



DiPLOCH^TE CoUins, 1901. Marine. Epiphytic. Cells ellip- 

 soid and somewhat flattened, solitary ; cell-ivall thick and homo- 

 geneous. Each cell furnished with 2 rather short, stiff, simple setcs, 

 arising from the lower half of the cell, usually at opposite poles. 



1. D. solitariaCoWm^. Diam. cell. 25-30 ju ; crass, cell, membr. 

 5-8 /x; long. set. 55-67 /x ; crass, has. set. 5-6 /x. 



Oligochaetophora, gen. n. Freshwater. Epiphytic. Cells 

 subglobose or ovoid, loosely aggregated to form very small colonies ; 

 cell-wall very thin and homogeneous. Each cell furnished wnth 

 2-4 long, flexuose, simple seta, of a delicate character and without 

 a sheath, arising only from the dorsal surface of the cell. Chloro- 

 plast single, parietal, possessing 2 or 3 small granules of starch. 



1. 0. simplex nob. [= Polychcetophora simplex G. S. West, 

 1908] . Diam. cell. 15-20 /x ; long. set. 50-210 (plerumque 120) /x; 

 crass, has. set. 0-6 fx. 



THE FLORA OF THE WORMS HEAD, 



AND THE NATIVITY OF CERTAIN DISPUTED SPECIES. 



By the Rev. H. J. Riddelsdell. 



Last June I spent three weeks at Rhosili, a village close to 

 the Worms Head, and at the western extremity of the peninsula 

 of Gower. The peninsula forms the western part of Glamorgan- 

 shire, and extends some eighteen miles west from Swansea. The 

 coast consists of lofty limestone cliffs, rising to more than 200 ft. 

 at Rhosili. North of the village the limestone is replaced by a 

 considerable hill of Old Red Sandstone, which forms a rocky 

 boggy heathland, producing Sedum anglicum, Drosera, Osmunda, 

 and the like. The hill ends seawards in low cliffs, fronted by a 

 good bay of smooth sand. 



The limestone cliffs extend from Rhosili south to tlie Worms 

 Journal of Botany. — Vol. 49. [March, 1911.] h 



