LAMPROTHAMNUS ALOPECUROIDES. 167 



the group grows most favourably on siliceous and aluminous soils ; 

 less so on limestone or chalk ; and in this respect it differs from 

 Chara. It will be worth while to examine the liassic and other 

 clay districts of the county for Tolypella, which has as yet escaped 

 notice. The roots of Characece are in the form of a rhizome, which 

 like the stem is articulated, the internodes being simple cells. The 

 plants are attached to the soil by very fine and slender rootlets. It 

 does not appear certain that the reproductive bulbil, the cells of 

 which are densely filled with starch-granules, are restricted only to 

 certain species of Chara. I have found them in Chara fragilis ; in 

 Lamprothamnus alopecuroides they are unicellular and exceedingly 

 small. In Chara fragifera the bulbils are distributed freely over 

 the whole plant. Until recently these plants had been found only 

 in a fossil state in the Tertiary formations ; they have lately been 

 found in the trias (muschelkalk) of Moscow in the Jurassic'and the 

 chalk. It is remarkable that all the species which have been found 

 in a fossil state agree completely with the living forms, not only in size 

 but in structure also, and especially in the fruit which are usually 

 well preserved. It must be consequently admitted that during the 

 lengthened duration of its existence the type has not undergone 

 modification. Well preserved impressions of Chara are rarely met 

 with, this may be easily explained when we take into consideration 

 the delicacy of its structure. The seeds on the other hand are 

 frequently met with in the Tertiaries ; but owing to the detachment 

 of the coronula, it is impossible to distinguish the genus 

 to which they belong. Mr. Clement Keid found at Hoxne, 

 in Suffolk, the seeds of Chara associated with fossil water-plants. 

 The types are similar to those of Iceland at the present day. The 

 seeds of Chara have been found, it is said, in the dirt-bed of the 

 Upper Purbecks, associated with Cycads and Conifers, as well as in 

 the Middle of Purbecks of Lul worth. 



