358 KIDSTON : THE FLORA OF THE CARBONIFEROUS PERIOD. 
maria, the rootlets bifurcated at the extremity though some may 
have been simple. 
The outer surface of the bark between the rootlet-scars bears 
an irregular reticulation of slightly raised ridges. This is probably 
produced by a sub-epidermal layer of sclerenchymatous tissue, the 
strands of which uniting amongst themselves form a net-like reticu- 
lation (Plate LL, fig. 5). The dense nature of this tissue would assert 
A 
Fig. 11. — Omphalopliloios anglicus Sternb. sp. A to E, from different 
portions of the same specimen (No. 426) ; F and G, portions of another 
example (No. 433) ; A, C, and F, natural size ; B, D, E, G, enlarged- 
all from Camerton, Somerset. For explanation of lettering see text. 
itself on the outer surface when the specimen was subjected to pressure 
and decay. The cast of the pith cavity is ribbed and somewhat in 
appearance like the cast of a Calamite, but without joints (Plate LIV., 
fig. 5). 
The genus is rare in Britain, but probably more common than 
suspected, as it may have been passed over for Stigmaria. 
The most important characters on which this genus stands are 
the Calamite-like ribbed cast of the pith cavity, and the irregular 
