CHARA. 



13 



1. Chara Knowltoni, sp. nov. 



Type. Imperfectly preserved oogonia discovered by Mr. Rufford 

 at Cliff End, near Hastings. British Museum. Registered number 

 V. 10700. Woodcut, Fig. 1. 



Oogonia broadly oval in form, the largest specimens about '5m. 

 long and approximately the same breadth at the broadest part. 

 Surface marked with eleven or twelve ridges, arranged in the 

 form of a flattened spiral very little removed from the horizontal. 



Fig. 1. Oogonium of Chara Knowltoni, sp. nov. (V. 10700), x 30. 



Each specimen is covered by a thin and brittle layer of car- 

 bonaceous matter, and in all probability the ridged surface is that 

 of the enveloping cells, the substance of which is left as a black 

 film moulded on the ridged and furrowed surface of the oospore. 



The examples on which this species is founded are confessedly 

 meagre, and hardly such as to warrant the institution of an 

 additional species. Such characters, however, as are available 

 indicate very clearly marked differences from the Wealden species 

 previously described. It may, therefore, serve a useful purpose 

 to designate the British specimens by a new name, provided the 

 fact be kept in mind that the material hitherto found in the 

 English beds is not at all adequate for the purposes of thorough 

 specific definition. I have ventured to name this species after 

 Mr. Knowlton, who has recently added to our knowledge of 

 fossil Charas. 



The present species differs from the other Wealden form, 

 Chara Jaccardi, in having many more surface ridges, and in its 

 more globular and less elongated shape. The globular form may, 

 however, as previously suggested, be, to a certain extent, the result 

 of flattening. 



A specimen figured by Squinabol ' from Tertiary beds of Liguria, 



1 Contrib. Fl. foss. Liguria, vol. ii. p. 7, pi. xii. figs 1 and 2. 



