THE FOSSIL FLORA OF THE YORKSHIRE COAL FIELD. 45 



From the structures here described, the spoon-like form of the bract, and the mode of 

 attachment of the " ovoid body," which appears from the enlarged figures to be 

 attached to the " knee " of the bract, I am afraid this cone cannot be placed in the 

 genus Sigillariostrobus ; and especially, in the light of the specimen given on my 

 pi. ii. fig. 3, Zeiller's cone, if my interpretation of it is correct, would require a new 

 genus to be created for its reception. 



One frequently finds on stems of certain Sigillarise curious scars, occasionally placed 

 in the hollow between the ribs, sometimes on the ribs and in the clathrate forms, inserted 

 between the leaf- cushions. These scars form a girdle round the stem, often of little 

 width, but occasionally of greater vertical extent. These are the scars left by the fallen 

 cones. In the majority of cases the cones appear to have been pedicellate ; # but in some 

 members of the Clathrarian section, as on Sigillaria (Ulodendron) discophora, and 

 Sigillaria ( Ulodendron) Taylori, the cones were sessile, and from the pressure of the 

 base of the cone on the bark, a cup-like depression was formed, which, after the cone 

 had fallen, increased in size with the increase of girth of the stem, in the same way that 

 we see our initials cut in the bark of a tree enlarge with the growth of the trunk. 



The mode of arrangement and disposition of these cone-scars on the stems of 

 Sigillarise afford important specific distinctions. Some have supposed these scars were 

 due to adventitious roots, but Renault has shown that small branchlets, bearing leaf 

 cicatrices, were attached to such scars on a specimen he describes from the Comentry 

 Coal Field,t so therefore the aerial-root hypothesis must be entirely abandoned. 

 When we add to this the discovery of pedicellate Sigillarian cones, the dimensions of 

 whose stems agree with that of the scars in question, the chain of evidence in favour of 

 these curious scars frequently found on the stems of Sigillaria, being the scars left by 

 the fall of deciduous pedicellate cones, seems complete. 



Some other writers than those already referred to have figured cones which they 

 believed to be those of Sigillaria. Of some of these, with only the figures and descrip- 

 tions to guide one in forming an opinion of their systematic position, there must rest 

 considerable doubt as to the accuracy of placing them in Sigillariostrobus. 



Mr Binney gives a woodcut of a fossil which he regards as the fructification of 

 Sigillaria, ~\. but neither his description nor figure show any evidence that his fossil had 

 any connection with Sigillaria, much less that it was a cone. 



In the Versteinerungen der bohmischen Kohlen-Ablagerungen, part iii. pp. 32-33, 

 1876, Feistmantel describes two species of Sigillariostrobus — S. Cordai, pi. xi. fig. 4, 

 and 5. Feistmanteli, pi. xi. figs. 1-3. These cones, from the fragments figured, must 

 have been of very large size, much larger than any we can definitely refer to this genus. 

 In no case is the complete bract shown, only the basal expanded portion. One has 

 considerable difficulty in accepting, without great reservation, the systematic position 



* See also Kidston, " On Sigillaria Brardii, Brongt., and its Variations," Proc. Roy. Phys. Soc, vol. xiii. p. 233. 

 t Flore foss. Bassin houil. d. Comentry, pp. 540-541. 

 X Phil. Tram., 1865, p. 595, fig. 6. 



