532 
Bancroft.—A Contribution to our 
the Botany School and Binney collections, at Cambridge ; Dr. W. T. 
Gordon, for the loan of slides, and for helpful discussion ; Miss T. L. 
Prankerd, for very kindly lending preparations and material of Hottonia 
palustris and H. inflata ; and other friends who have supplied literature, 
and material of recent plants for comparative purposes. 
II. Distribution and Horizon of R. cylindrica. 
The distribution of Rachiopteris cylindrica appears to be restricted 
to the Halifax-Huddersfield area, where it occurs in the Halifax Hard Bed 
of Lower Coal Measure Age. 1 
Williamson, who originally described the species in 1878, 2 remarked 
that he had never discovered it in the Oldham nodules ; and a search 
through various collections comprising both old and recently acquired 
material has failed to reveal a single authentic specimen recorded from 
any other locality than that mentioned above. 
In the case of a few specimens in the Williamson and Manchester 
collections no locality is given, but the general aspect and colour of the 
plant tissues indicate that this material also was obtained from the Halifax 
Hard Bed. 
R. cylindrica is found in the nodules of the coal seam, and its excellent 
preservation suggests that it was petrified more or less in situ. The outer 
layers of the stem, it is true, are frequently somewhat crushed and eroded, 
but not more than is to be expected from compression and contact with 
other plant remains during turf formation. 3 In other cases, the outer tissues 
of the stem, with delicate hairs, are well preserved. 
Doubtless, further working of the coal strata will extend our knowledge 
of the occurrence of R. cylindrica , but the material at present available 
indicates that this plant had a localized distribution. 
III. Detailed Description of the Organs of R. cylindrica . 
An idea as to the structure and morphology of Rachiopteris cylindrica 
is drawn from the certain evidence of direct connexion between stems, 
roots, and primary petioles ; and from the suggestive evidence of more 
or less constantly associated axial structures, and sporangia of Fern type. 
The first class of evidence, owing to the favourable preservation of the 
material, may be considered in detail 
1 See Geological Ordnance Survey Map, No. 88 N.E. 
2 Williamson, W. C.: On the Organization of the Fossil Plants of the Coal Measures. Pt. ix, 
Phil. Trans. Roy. Soc., B, vol. 169 , 1878 , p. 319 . See p. 351 . 
3 Stopes, M. C., and Watson, D. M. S. : On the Present Distribution and Origin of the 
Calcareous Concretions in Coal Seams, known as ‘ Coal Balls Phil, Trans, Roy. Soc., B, vol. 200 , 
1908 , p. 167 . See p. 173 
