244 Mr, R. Bullen Newton on some 



My grateful thanks are due for tlie following additional 

 and more technical notes on the Charophyte-remains con- 

 tained in these rocks, which have been kindly drawn up by 

 Mr. James Groves, F.L.8., one of our cliief autliorities on the 

 morpiiology of recent Characeous Plants : — 



Rock no. 13j0. — This shows what is probably an oospore 

 with a dark margin representing a section of the enclosing 

 spiial colls which constitute the oogonium-sac. It is of small 

 dimensions, being about '45 x '35 mm. The spaces between 

 the spiral lines are somewhat convex, although this may 

 be due to being chalcedonized. The outline of the margin 

 corresponds roughly with the impressions of associated oogonia 

 measuring '775 x '525 mm. There is another supposed 

 oogonium or a larger oospore ahout two-fitths of which is 

 exposed, having a definite surrounding margin of dark 

 mineralized matter and showing a.diameter of '425 mm. The 

 crushed oogonium (or oospore) in close proximity has, appa- 

 rently, a much tapered base (PI. YIII. fig. 6). 



Rock no. 1351. — Contains a large oogonium, which, on 

 account of its size, would be a different species to that seen in 

 no. 1350. It is probably 1 X "6 mm. The branchlets near 

 by are about •2G-'3 mm. in diameter. A microscopical slide 

 cut from this rock exhibits a good diagonal section of a 

 branchlet (or small stem) with a diameter of about '4 mm. 

 and possessing a probable diplostichous cortex, as it consists 

 of about fourteen cells in section (PI. VIII. fig. 7). Certain 

 small cylinders, considered to be bract-ceils, show a diameter 

 of about •2-*3 mm., but no branchlet-node was observed. 

 Another stem or branchlet section gives a diameter of about 

 •6 mm. A further microscopical slide shows n good trans- 

 verse section of stem with a diameter (including cortex) of 

 about '45 mm. The cortex is almost certainly diplostichous, 

 cells fourteen and of nearly equal diameter ("03 mm.). The 

 smaller ecorticate sections may be both branchlets and bract- 

 cells, although, from their position, there is no indication of 

 whorls. 



Rock no. 1352. — The Chara remains on the surface of this 

 specimen belonged probably to a medium-sized plant of about 

 the stature of the living Chara vulgaris. 



Stem moderately stout, about •65-'90 mm. in diameter. 

 Cortex triplo.stichous, rather irregular, j)rimary series some- 

 times much the larger, but secondary cells of varying diameter. 

 No cortex nodes determinable. 



