32 



PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Nov, 2, 



the rootlets, is no doubt a special provision for growth in soft and 

 homogeneous alluvial soils and peaty muck. The curious resemblance 

 of these roots to the cable-like rhizomata of the pond-hly*, vpould 

 lead us to infer that their form and structure were intended rather 

 to obviate the effects of excessive moisture, than to collect large 

 supplies of liquid nutriment. 



A nodule of ironstone from one of the underclays shows, though 

 somewhat imperfectly, the structure of the rootlets or great hollow 

 spongioles of Stigmaria. Fig. 11a, ms. is a slice of the natural size. 

 The outer circle is the original form of the rootlet, now filled with 

 clear calc-spar. Within this is the shrunken rootlet, in a carbonized 

 state. Fig. 116, ms. represents the remains of the rootlet magnified, 

 and showing an outer and inner cuticle with intervening cellular 

 tissue having open spaces. Fig. lie, ms. is a portion still more 

 highly magnified. 



Different opinions have been entertained respecting the mode of 

 growth of Sigillarice, owing to the supposed uniformity of the ribs 

 and leaf-scars along the whole length of the trunk. Mr. Binney, 

 however, remarks, that a specimen in the Manchester Museum shows 

 four kinds of leaf-scars. The most distinctly marked erect trunk 

 found by us in the Joggins Section affords an interesting illustration 

 of this variety of marking. At the height of 5 feet above the base, 



Figs. 9, 10, & 1 1. — Ribs andLeaf-scars of erect Sigillaria stump, from 

 the South Joggins. 



Fig. 10. 

 Fig. 9. 



illiilliiliiilt'i'iliy 



At 5 feet from the root. 







li 



illl 









«KI 



II 

 I 





1! 





1 



1 





1 

 1 



1 ' 



At from 2 to 3 feet from the root. 



Fig. 11. 



Near the root. 



the hgneous surface has deeply marked ribs and oval leaf-scars. A 



little lower it has broader and flatter ribs, with broad scars somewhat 



* Nymphaea odorata. 



