On Mesostrobus, a New Genus of Lycopodiaceous 
Cones from the Lower Coal Measures, with a Note 
on the Systematic Position of Spencerites. 
BY 
D. M. S. WATSON, B.Sc., 
Beyer Fellow of the Geological Department of the Victoria University of Manchester. 
With Plate XXVII, and six Figures in the Text. 
I N 1907 the Manchester Museum received from Mr. Lomax, of Bolton, 
a series of four transverse sections of a cone from the Mountain 4 ft. 
Mine of Cloughfoot, Dulesgate. Mr. Lomax had recognized the specific 
distinction of the cone from all yet described, and has published a photo- 
graph of a section in a work on Coal, by Mr. J. Tonge. Prof. Weiss very 
kindly handed the sections over to me, and I now wish to offer some 
description of them. 
Of the four sections, the uppermost only shows the sterile portion at 
the top of the cone, and the lowest is through a part of the cone that had 
been badly damaged before fossilization ; only the middle two are therefore 
of much use in gaining an idea of the arrangement of the parts of the cone, 
and one of these two has somewhat broken up during the process of grind- 
ing the section. The sections are, however, enough to enable one to give 
a fairly complete account of the whole structure of the cone. The axis 
of the cone is 2-6 mm. in diameter (PI. XXVII, Phot. 1). 
The wood is small, only 0-34 mm. in diameter, and is solid, there being 
no pith (Phot. 3 and 4 xy). The protoxylems apparently do not project much, 
and are not very well preserved. The main mass of the wood is composed 
of tracheids of nearly equal lumen, which do not seem to pass by any easy 
transition to the smaller tracheids of the protoxylem, which appear to form 
small groups on the outside edge of the wood. The wood is succeeded by 
an ill-preserved belt of tissue which includes, no doubt, the phloem and 
(?) pericycle (Phot. 4). This layer shows that the phloem was broken up by 
patches of parenchyma on the inside of the leaf traces in the way common 
in the Lepidodendra. 
[Annals of Botany, Vol. XXIII. No. XCI. July, 1909. 
