"^Il] CHARA. 227 



abundant! in the Chert beds of Purbeck age seen in the clififs 

 near Swanage. Pieces of corticated stems from this locality are 

 represented in fig. 45 A and B. 



The cortical cells surrounding a large internodal cell are 

 very clearly seen in the section shown in fig. 45 B, and in the 

 longitudiaal view in fig. 45 A. The resemblance of these 

 specimens to the stems of recent Stoneworts is very striking. 



Fig. 47. CTsara Knowltoni, Sew. x 30. 



The single oogonium of fig. 47 was found in the Wealden 

 beds near Hastings. 



3. Chara Wrighti, Forbes. Fig. 46, d and e. This species 

 is characterised by globular or somewhat elliptical oogonia, with 

 six or seven spiral bands. 



It is very abundant in the Lower Headon beds of 

 Hordwell Cliffs on the Hampshire coast ^. Various species of 

 Chara are commonly met with in the Oligocene beds of the 

 Isle of Wight and Hampshire, as well as in the Paris basin 

 beds, and elsewhere. Well preserved 'fruits' and stem frag- 

 ments are met with in a siliceous rock of Upper Oligocene age 

 imported from Montmorency in the Paris basin, and used as a 

 stone for grinding phosphates at some chemical works near 

 Upware, a few miles from Cambridge. 



Many other species of fossil Charas are known from various 

 horizons and localities, but the above examples sufiice as 

 illustrative types. In Post-Tertiary deposits masses of Chara 

 and plant fragments occasionally occur forming blocks of 

 Travertine. Examples of such Chara beds have been recorded 

 by Sharpe fi-om Northampton', by Lyell* from Forfarshire, and 



1 Woodward, H. B. (95) pp, 234, 261, etc. 



2 Forbes, E. (56) p. 160, PI. vii. 



3 Vide p. 69, fig. 10. 

 * LyeU (29). 



15—2 



