Fossil Fruits of Chara. (_Gyrogonites._) _Lign. 66._--The Chara is a well-known inhabitant of almost every stream and rivulet. The stems are hollow, and composed of tubes filled with a fluid in which green globules circulate; they form beautiful microscopic objects for exhibiting the circulation in vegetables. The fruit consists of very small nuclei, contained in a calcareous pericarp, composed of five spirally twisted plates, that unite at the summit. These seed-vessels, when first discovered in a fossil state, were supposed to be the shells of mollusks, and a genus was formed for their reception with the name of _Gyrogonites_ (_twisted-stones_); a term still employed, though the vegetable nature of these bodies is well known. In _Plate III. fig. 5_, a branch of the common Chara with seeds is represented: and figures of the seed-vessels, of two fossil species are given in _Lign. 66, figs. 1, 2_. Specimens of the fossil fruits and stems of Charæ, may be collected in abundance in the fresh-water limestone at East Cliff Bay, Isle of Wight.[171] [171] See my Geology of the Isle of Wight, _Lign. 5_, p. 109. [Illustration: Lign. 66. Fossil Fresh-water Plants. _Eocene, Paris._ Fig. 1.--Seed-vessel of _Chara helicteres_ × 10; side view. 1_a_.--View of the base of the same. 1_b_.--One of the spiral valves separated. 1_c_.--View from above. 2.--Seed-vessel of _Chara medicaginula_ × 10. The upper figure is a side view: the lower, a view of the base. 3.--_Carpolithes ovulum_, magnified side view. 3_a_.--The same, natural size. 3_b_.--Magnified view of the base of the same. 4.--A piece of fresh-water limestone, with impressions of two stems of _Nymphea arethusa_ ×. ] The _Purbeck beds_ at Durlstone Bay, near Swanage, also contain numerous Gyrogonites associated with fresh-water shells. The bands of siliceous sinter, which occur in the lowermost deposits, are especially rich in these remains.[172] [172] I am indebted to the Rev. Osmond Fisher, of Dorchester, for a fine suite of these and other interesting fossils from the Purbeck beds of Ridgway and Osmington, near Weymouth; and to William Shipp, Esq., of Blandford, and Edward Woodhouse, Esq., of Ansty, for many specimens from Durlstone Bay, and Ridgway.