SEAL : FOSSIL PLANTS. 
163 
sionally met with in the Mexborough rocks, but those I have 
seen are very small in comparison to the Darfield speci- 
mens. 
The position of these rocks runs north-west by north, 
and at Darfield they are 150 feet above the level of the sea. 
The most common fossil is the Calamite cannoeformis, 
so called from the reed-like jointings of its stem. It 
is found about twenty- five feet from the surface, and 
generally in a horizontal position. Hugh Miller says these 
organisms are never found in ironstone measures, and he is 
probably correct; but some of the specimens from these 
quarries contain a large percentage of iron. They are eleven 
inches in circumference, and are fluted vertically with from 
104 to 130 ribs : the joints are generally from two to two and 
a half inches apart. In these specimens we have little or no 
trace of an}' bark. Other specimens do not contain iron, but 
are pure siliceous grit, containing nothing of their once vege- 
table nature except the form. This species I consider to 
have been less ligneous than the Calamites mougeotii, which is 
occasionally found, and presents an appearance of having 
been burst or flattened. Its joints are more numerous than 
in cannoeformis ; and, from the occurrence of small holes in 
the joints, stems or leaves appear to have branched out from 
each joint, throwing off foliage forming canopies one above the 
other. Perhaps I may be permitted to remark that some of 
the designs now used, and many that are obsolete, have had 
their origin in the wonderful works of creation. I am told 
that the handles of some of the early specimens of Sheffield 
cutlery known as " Irish Cooks" are exact imitations of one 
species of Calamite. 
I now notice the Sigillaria. I believe more than twenty 
different species have been enumerated from the British coal- 
fields, but I have not noticed more than five or six kinds 
in the Darfield rocks ; but the specimens there are, I 
