6 
HICK : OUR KNOWLEDGE OF THE YORKSHIRE CALAMITY. 
The axial structure of this fruit seems sufficient to bring it into 
close relation with Arthropitys, as is confidently done by Williamson, 
but the insertion of the sporangiophores is so different from that of 
Equisetum, with which Arthropitys agrees in so many respects, that 
we cannot but wish that further specimens were forthcoming. Up 
to the present time only a few specimens have been discovered from 
the Lancashire Coal Measures, and we can therefore scarcely deter- 
mine whether or not they represent the normal state of things. As 
Arthropitys is a Yorkshire as well as a Lancashire type, it is surely 
not extravagant to think that if our Coal Measures were carefully and 
persistently searched, the search would be rewarded with additional 
examples of this most interesting spike. 
Our Yorkshire beds have, however, yielded numerous examples 
of the strobili, which are known under the name of Calamostachys, 
and which were dealt with at some length in a valuable paper con- 
tributed to the Proceedings of this Society by Mr. Cash in 1887. : ' : 
In its general structure, and even in a large number of details, this 
spike approaches so closely to the sporiferous spike of Equisetum, 
that it might be said to be almost exactly similar to it. But to say 
this, would be to ignore the fact that its axis is not yet as fully 
known as it ought to be before such an assertion would be scientific- 
ally justified. In the paper referred to, the views of several 
authorities with respect to Calamostachys are carefully collated, and 
it is shown that they are widely at variance with one another. 
Prof. Williamson is quoted as being of opinion " that Calamostachys 
Binneyana has much closer affinities with Asterophyllites than with 
Calajnites," and elsewheref the same authority has expressed his 
conviction that its true affinities are with the Lycopodiacecc.% This 
determination it may be mentioned was based, in the main, upon the 
structure of the axis of the fruit, which may be regarded as the 
critical feature where its affinities are concerned. Recently, however, 
Williamson has seen reason to modify these views and in the " General 
* Proc. of the Yorks. Geol. and Polyt. Soc, 1887, p. 444. 
f Philosophical Transactions, 1881, p. 299. 
X At the time this opinion was expressed, Williamson regarded Asterophyllites 
as Lycopodiaceous. 
