'16 BRITISH CHAROPHYTA. 



the upper usually very long, slender and acuminate, 

 the lower usually similar, but sometimes shorter and 

 blunter. Branchlets short, slightly incurved, of 5-8 

 segments, all but the last usually corticate, the cortex 

 1 -ranked, ultimate segment often scarcely exceeding the 

 subtending bract-cells. Bract-cells usually 5-6, all 

 well-developed and exceeding the oogonium, slender 

 acuminate ; bracteoles usually very short, but occasionally 

 longer than the fruit ; bractlet* minute, sometimes rudi- 

 mentary. Oogonium ellipsoid to ellipsoid-elongate, c. 

 600-750 ji, long, 400-500 fx thick ; spiral-cells showing 

 13-15 convolutions ; coronula short, c. 50-80 (x high, 

 100-150 [i. broad, straight or slightly connivent. Oospore 

 ellipsoid-obovoid or ellipsoid-cylindrical, c. 450-625 [i 

 long, 275-400 [i thick, black, showing 10-13 low incon- 

 spicuous ridges terminating in short basal claws ; outer 

 membrane thick, brittle, opaque, very dark red, very 

 finely granulated. [Antheridium c. 600-650 [i in dia- 

 meter. The male plant has not hitherto been found in 

 the British Isles.] 



Habitat. — Lakes and pools near the sea, rare, 

 occurring in -a few scattered localities in the South and 

 East of England and the West and South-East of Ireland, 

 and in one locality in the extreme North of Scotland. 



Distribution. — England : Cornwall, W., Budock 

 Pool, near Falmouth, W. L. P. Garnons, 1841 ; small 

 pool near Kynance Cove, J. Guardia <& H. Groves. 

 Dorset, Little Sea, Studland, Bolton King ; clay-pit, 

 near Hamworthy, E. F. Linton. Kent, E., Birchington, 

 G. 0. Allen. Sufiolk, E., Easton and Benacre Broads, 

 E. S. & C. E. Salmon. Norfolk, E., Hickling Broad, 

 G. R. B.-W. 



Scotland : Orkney, Loch of Stenness, Mainland, 

 H. H. Johnston & G. C. Druce. 



Ireland : Kerry, S., Castle Gregory Lake, R. W. 

 Scully. Wexford, lagoon North of Wexford Harbour, 

 E. S. Marshall. Galway, N. E., Saltmarsh-pool East 



* The term bracUet is appKed to the small central elongated cell below the 

 oogonium, which, in dioecious species, takes the place of the antheridium. 



