198 kidston: the flora of the carboniferous period. 
made in the study of palaeozoic botany, and to the Cycadofilices 
are known to belong certain Spheiiopteris, Alethopteris, and 
Neuropteris. 
As an example of how step by step our knowledge of 
palaeozoic botany is built up, it may be mentioned that the 
petioles described by Williamson as Rachiopteris aspera were 
subsequently found to belong to the stem named Lyginodendron 
Oldhamium by the same author, and further it has been dis- 
covered that Lyginodendron Oldhamium is the stem of the 
well-known Sphenopteris Hoeninghausi Brongt. (Plate XXIX., 
fig. 5). Could any better example be found of the result — or 
reward — of patient, plodding work, or of the provisional nature 
of genera founded on the vegetative organs ? 
CALAMARIEiE, 
Equisetites Sternberg. 
A few fossils have been found in Carboniferous rocks which 
from their great external resemblance to the recent Equisetum 
or Horsetails, have been placed in a genus called Equisetites by 
Sternberg. These fossils are extremely rare, and as far as at 
present known do not go further back than the Coal Measures. 
One of the most interesting examples of the genus is the 
Equisetites Hemingwayi (Plate XXXIV., fig. 3), which was dis- 
covered by Mr. Hemingway, Barnsley. 
The cones are oval, about one inch long and rather over 
half an inch broad. The outer surface of the cone is covered 
with hexagonal scales about one-fifth inch in diameter, with a 
small central point, indicating probably the place of attachment 
of the little pedicel by which the peltate shield was united to 
the axis of the cone. Nothing is known of the inner structure 
and arrangement of the sporangia, but the' external appearance 
of Equisetites Hemingwayi is so like that of the cones of recent 
Equisetum (of which a figure is given for comparison, Plate 
XXXIY., fig. 4, Equisetum hyemale), that the affinities of 
Equisetites Hemingwayi Kidston with Equisetum is probably 
very close. 
