THE GENUS POLYSIPHONIA. 301 
of the ramuli. Cystocarps sessile, ovate in form, borne on the smaller 
branches. 
Antheridia are not recorded by Harvey (l. e.), Agardh (l e.), or De Toni 
(l. e.), but were observed in a specimen in the Batters collection in the 
Natural History Museum, South Kensington. 
Habitat. Occurring on rocks, stones, and other algæ, such as Rytiphlæa 
pinastroides, in clear sunny tide-pools and also in deep water. Rare, but 
occurring in considerable quantity at uncertain intervals. 
British Records. Orkney Islands, Stonehaven, Earlsferry, Dunbar, 
Berwick, Whitley, Roker, Cromer, Brighton, Shoreham, Isle of Wight, 
Swanage, Weymouth, Seaton, Sidmouth, Torquay, Plymouth, Looe, Fal- 
mouth, Mount’s Bay, St. Minver, Isle of Man, Anglesea, Salteoats, Isles of 
Arran, Bute and Cumbrae, Loch Coil, Bangor (Co. Down), Howth, Bantry, 
Miltown Malbay, Roundstone, and the Channel Islands. 
Distribution in Europe. Atlantic shores, Baltic and Mediterranean Seas. 
5. P. spınunosa Grev. Scottish Cryptogamie Flora, vol. ii. 1824, p. 90. 
Reference. Agardh (2) ii. p. 999. 
Icones. Greville, Scottish Crypt. Fl. ii. 1824, pl. 90. Harvey, Phyc. Brit. 
1846-1851, pl. 320. syn. 110. 
DescRIPTION.— Habit. Plant about 5 ems. in height. Branched from the 
base, branches arising alternately, clothed with short spine-like ramuli, each 
bearing a cluster of dichotomising fibrillæ at the tip. Siphons. 4 primary 
pericentral, alternating with which are 4 secondary, bounded by a row of 
corticating cells. Colour. Dark red. Anatomy. Articulations visible through- 
out the plant, their length being about equal to their breadth. Reproductive 
organs. Cystocarps sessile and ovate in form, occurring on the branches 
and ramuli. 
P. SPINULOSA var. 8. MAJOR, J. G. Ag. Spec. Alg. ii. 1863, p. 999. 
— P. Carmichaeliana Harv. in Smith’s Engl. Flora, v. 1833, p. 328. 
Reference. Harvey (28) pl. 319. syn. 116. 
This variety occurs on Desmarestia aculeata, and has been recorded by 
Captain Carmichael from Appin, and records have also been made from 
Little Cumbrae and Skaill, although the plant is very rare. The growth is 
more lax than that of P. spinulosa. There is a central axis from which the 
branches arise, rather similar to that of P. fibrillosa, but the branching is 
more delicate. A wider band of corticating cells occurs than is present in 
P. spinulosa. 
Habitat. Probably in tide-pools. Rare. 
British Records. Appin, Argyll (Carmichael’s spec. in Herb. Hook., 
Kew). 
Distribution in Europe, Nil. 
