ORGANIZATION OF THE FOSSIL PLANTS OF THE COAL-MEASURES. 933 
4. The occurrence of very large elements, resembling sieve-tubes, in the phloém- 
region. 
These characters are sufficient to differentiate the species. In the arrangement of 
the leaves, the outline and structure of the primary cortex, the centripetal triarch 
xylem, and the mode of growth in thickness, the plant is a typical Sphenophyllum, in 
which genus it finds its natural resting-place. 
THE FRUCTIFICATION OF SPHENOPHYLLUM. 
SPHENOPHYLLUM Dawson, NOBIS. 
The fructification which we are about to consider was first described in 1871, under 
the name of Volkmannia Dawsont, unless, indeed, as M. ZEILLER suspects, the plant 
described by Binney, in the previous year, as Bowmamnites cambrensis, be the same 
species.* 
Further accounts of the same fossi] were published in 1873 and 1890, and, in 1891, 
a very complete description was given of its structure, on the basis of a number of 
newly-discovered specimens.t 
In 1884 the species was placed by Weiss in BiInNEY’s genus Bowmanites,{ a view 
which was accepted in the later memoirs of WILLIAMSON. 
In 1892, M. Zemier§ communicated to the French Academy the results of his 
examination of some extremely fine fructifying specimens of Sphenophyllum cunei- 
folium, Stekns., from the French and Belgian Coal-Measures. He expressed himself 
as convinced of the complete identity of WutLiamson’s specimens of Bowmanites 
Dawsoni, with the fructifications of his Sphenophyllum.|| 
This year (1893) M. Zeinter has published his work in full! His detailed 
descriptions, and especially his beautiful photographic illustrations, leave no doubt as 
to the essential agreement between the undoubted strobili of Sphenophyllum, which 
he investigated, and the English specimens described as Bowmanites Dawsoni. The 
question of specific identity of the latter with Sphenophyllum cunetfolium, is one 
which we prefer to leave open for the present. One of us (D. H. Scorr) has had the 
* Wiuramsoy, “On the Organization of Volkmannia Dawsoni,” ‘Mem. Lit. and Phil. Soc. of Man- 
chester,’ Ser. 3, vol. 5; Brywey, “ Observations on the Structure of Fossil Plants,” Part 2, ‘ Paleonto- 
graphical Society,’ volume for 1870. 
+ Wititamson, “ Organization of Fossil Plants of the Coal-Measures,” Part V. (1873); Part 17 (1890) ; 
and Part 18 (1891); ‘ Phil. Trans.’ 
+ Weiss, ‘ Steinkohlen-Calamarien,’ vol. 2, p. 200. 
§ ‘Comptes Rendus,’ vol. 115, July 11, 1892. ; 
|| This conclusion has already been provisionally accepted by WILLIAMSON, * Nature,’ vol. 47, Nov. 3, 
1892. 
q ‘Etude sur la constitution de l'appareil fructificatear des Sphénophyllum,” ‘Mém. de la Soe. 
Géol. de France; Paléontologie,’ Mém. 11, 1893. 
