GEOLOGICAL HISTORY OF THE CHAROPHYTA. 77 



certain vegetative remains (see Fig. 28) exhibitiag points 

 of resemblance to the Charophyta, and which may well 

 belong to that group. It is much to be hoped that 

 further search may bring to light specimens with 

 gametangia. The wonderful state of preservation of 

 fossils in this bed renders their minute cellular structure 

 clearly visible, and should the plant in question prove 

 to be a Charophyte, it rniay throw a very important 

 light on the early history and affinities of the group. 

 The double-foot processes on the rhizoids of the fossil 

 (see Fig. 286) are very like those of living Charophytes. 

 The plant described by Stur (25) as a new genus, 

 Barrandeina, from beds now regarded as Middle 

 Devonian, in Bohemia, and placed by him under " Ordo 

 CharacecB prcecursores," does not, as far as one can 



Fig. 29. — Palxocliara acadica. Bell (after Bell), from the Coal 

 Measures of Nova Scotia, a, side view ; b, view of basal end ; 

 c, longitudinal section, all " 26. 



judge from the author's rather obscure illustrations, 

 show any clear affinity to the group. 



Carboniferous.— in 1922 Dr. W. A. Bell (1) pub- 

 lished an account of the very important discovery, in 

 the Lower Coal Measures of Nova Scotia, of what appear 

 to be undoubtedly the oogonia of a Charophyte, to 

 which he has given the name Palceochara acadica (see 

 Fig. 29). These represent the earUest remams which 

 can with any degree of confidence be at present assigned 

 to the group. The structure of the fruits is similar to 

 that of existing types, except that the number of spiral- 

 cells is six instead of five. I am greatly indebted to 

 Dr. Bell for specimens of these fruits. 



Some spherical organisms with faint spiral markings 

 have been found in the Calciferous Sandstone of Fife 



