FRESH-WATER PLANTS. FOSSIL CHAR. 195 
uncertain: the external resemblance to the stem of the 
Draczena consists in the interrupted annular ridges, denot- 
_ ing amplexicaul leaves : no vestiges of the foliage have been 
observed. 
Foss, FRresH-waTEeR Puants.—The tertiary fresh-water 
_ strata often contain abundance of the remains of the aquatic 
_ vegetables that inhabited the lakes and rivers in which 
those deposits were formed. The remains of several species 
of the common lacustrine plant, the Chara, are found in 
immense quantities in the fresh-water limestones and marls 
of the Isle of Wight, of the coast of Hampshire, and of the 
Paris Basin. The shell-marls, still in progress of formation 
in the lakes of Scotland, and the travertine precipitated 
from thermal springs, in like manner envelop and preserve 
the leaves and fruits of recent species. 
Fossin Fruits or Cuara. (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 circu- 
lation 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 I/J/. jig. 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, 
jigs. 1, 2. 
Specimens of the fossil fruits and stems of Chare, may 
be collected in abundance in the fresh-water limestone at 
East Cliff Bay, Isle of Wight.* 
* See my Geology of the Isle of Wight, Lign. 5, p. 109. 
