AGLAOPHENIA PLUMA. 287 



which enclose the reproductive capsules. I have seen fine 

 Devonshire specimens in which the plumes measured 

 three-quarters of an inch across, and were most elegantly 

 curved. 



The pinnae are of a lighter colour than the stem,, and 

 are set forward upon it, so that the pairs form a series of 

 obtuse angles ; and the plume is somewhat carinated below. 

 Each pinna is slightly arched, and the shoot itself is gene- 

 rally recurved; so that the whole structure is bounded 

 and pervaded by lines of beauty. 



A variety (ft)* occurs, of very delicate habit, in which the 

 stem divides and subdivides dichotomously, each branch 

 being plumose and pinnate. 



Hab. On weeds, especially Halidrys siliquosa, and occa- 

 sionally on shells, rocks, Sec. ; between tide-marks, and in 

 the Laminarian zone. 



A. pluma is much more at home in the south and west 

 than in the north. We have no record of its occurrence 

 in Shetland, nor has Mr. Peach met with it at Peterhead 

 or Wick. Throughout the north it seems to be sparingly 

 distributed, whilst along the south-western coasts it is 

 extremely abundant and of great size and beauty. Be- 

 tween tide-marks it is of humbler growth, and is found 

 covering the surface of the rock, or investing the roots 

 and stems of Laminaria. 



Westra, Orkney Islands (Lieut. Thomas) : Ayrshire, 

 often cast in after storms (D. L.): Whitburn Bay, North- 

 umberland (a single specimen found) (J. A.) : Filey, not 

 common (T. H.): Mersey, occasionally on Halidrys (Dr. 

 Collingwood) : Barmouth (J. Gr. Jeffreys): Isle of Man 

 (T. H.) : around the coast of Ireland (W. T.) : Dover 

 (Lister) : Jersey (A. M. N.) : Devon and Cornwall, very 



* Var. dichotomn, Sars, Middelha vet's Litt. Fauna, 55. 



