292 
hick: oalamostachys binneyana. 
with in the stems and leaves of Arthropitys as well as in the bracts 
of Calamostackys Binneyana which seem to me significant of their 
close relationship. In a paper published by Mr. W. Cash and myself 
in the Proceedings of the Yorkshire Geological and Polytechnic 
Society* in 1883, attention was called to a layer of tissue outside the 
zone of xylem in the stem of Catamites (Arthropitys), which presents 
several peculiarities. Two of these are the presence of a number of 
large elements among others of smaller size, and the presence within 
some of the former of black and apparently carbonaceous masses. 
Since that time a large number of young stems have come under 
observation, and they all exhibit this layer as a characteristic mark 
of their anatomy. It is practically continuous round the whole stem, 
and is sharply distinguished by its open texture, so to speak, and the 
black contents from the tissues on the inside and the outside. In 
its histological details it bears the closest possible resemblance to the 
layer of large elements described in this papert as commencing at the 
periphery of the nodal disks of Calamostackys Binneyana, and as 
forming the lower half of the transverse sections of the bracts. In 
other words, while having the same general appearance, it presents 
the same variability in the size and shape of its elements, which are 
united without intercellular spaces, and in many cases have similar 
black contents. 
But this is not all. In a large series of preparations of 
Arthropitys which Mr. W. Cash has placed in my hands, small stem- 
are found associated with leaves in a manner which is demonstrative 
that they belong to the same foliage shoot. Mr. Lomax too has 
kindly allowed me to examine several preparations from his cabinet, 
which likewise show small stems and leaves in such positions as to 
prove that they belong to one another. Now in all these preparations 
the leaves of Arthropitys are characterised by a layer of tissue which 
is histologically the same as that just described in the stem, and 
which is so conspicuous a feature in the bracts of Galamostachys 
Binneyana. Thus a tissue which is characteristic of the bracts of 
the sporiferous spike with wdiich we are dealing is characteristic also 
* Vol. xix., 1883, pp. 85-92. 
t Ante, pp. 286-287. 
