308 DR. LILY BATTEN ON 
small branches, arising near the original attachment organ. A disc-like 
expansion develops by the mechanical interlocking of the expanded bases of 
the rhizoids. Reproductive organs. Tetraspores small, intercalary. Antberidia 
occurring in large numbers near the tips of the branches. Cystocarps occur- 
ring on the smaller branches and ramuli, broadly ovate at the base and shortly 
stalked. 
A floating species found in September (Cotton) in the lake of Poole Park 
exhibited marked dichotomy in the lower branches, and the articulations 
consisted of six pericentral siphons and a central one. No cortication was 
present, The mud-loving estuarine habit of the plant confirms the decision 
that the plants found were floating forms of P. variegata. 
Habitat. A mud-loving estuarine species occurring on rocks, stones, and on 
smaller algæ such as Chorda filum and on the leaves of Zostera. Very rare. 
British Records. Brighton, Isle of Wight, Studland (Batten), Swanage 
(Batten), Weymouth, Plymouth, Torpoint, and St. Minver. 
Distribution in Europe. Atlantic shores of France and Spain, Mediterranean 
and Adriatic Seas. 
BIBLIOGRAPHY. 
. AGARDH, J. G.-—Alge maris mediterranei et adriatici. Paris, 1842. 
— Species, Genera et ordines Algarum. Lunda, 1848-1876-1901. 
——— Florideernes Morphologi, Stockholm, 1879. 
. AGARDH, C. A.—Systema Algarum, 1824, 
—— -— Synopsis Algarum Sgandinavie. 1817. 
——— Species Algarum. 1828, 1828. 
. ARDISSONE, F.—Le Floridee italiche. Milano, 1869-78. 
. ARESCHOUG, J, E.—Phyceæ Scandinavicæ marine. Upsala, 1850. 
. Barrers, E. A. L.— Catalogue of British Marine Algw. 1902. (Supplement to 
Journ. of Bot.) , 
. Bonnemaison, M. T.—Essai sur les Hydrophytes loculées. Journ. de Physique, Paris, 
1822, 
. Borner, E.—Les Algues de P. K. A. Schousboe. Paris, 1892. (Mém. Soc. Sei. 
Cherbourg, xxviii. pp. 165-370, 8 pls.), 1892. 
. Bornet, E., & G. THunET.— Recherches sur la fécondation des Floridées. Annales des 
Sciences Naturelles, Botanique, 5° série, tom. vii. 1867, pp. 137-166. 
. BREBNER, G.—On the Origin of the Filamentous Thallus of Dumontia filiformis. 
Journ. Linn. Soc. xxx. 1895. 
. CHURCH, A. H.-—Historical Review of the Florideæ. Journ. of Bot. lvii. pp. 297 et seq., 
329 et seq. 
© © 1 O 1 PWD m 
m T i 
© N rH Oo 
bi 
rs 
15. Cocks, J.—Algarum Fasciculi: a Collection of British Seaweeds. 1855-60. 18 fascicles. 
16. Corron, A. D.—Clare Island Survey. Alga. Proc. Roy, Irish Ac. xxxi. pt. 15, 1912, 
17. Crovan, P. L., & H. M. Crovan.—Florule du Finistère, Paris, 1867. 
18. - Algues marines du Finistère. Paris, 1852. 
19. DERBÈS, A., & A. J. J. Sorrkr.—Physiologie des Algues. C. R. Acad. Sci. Paris, i. 
1856. 
20. Derick, C. M.—Holdfasts of Florideæ. Bot. Gaz. xxviii, 1899, p. 251. 
