KIDSTOX : THE FLORA OF THE CARBONIFEROUS PERIOD. 359 
mesh-like markings on the outer surface of the bark. The corre- 
sponding cast of the pith cavity of Stigmaria would, on the other 
hand, show the impression of the surrounding netted cylinder, the 
openings in the mesh being the channels through which the primary 
medullary rays passed out. The character of the pith cast can, 
however, be seldom observed, and in its absence one has only the 
reticulated or wavy ornamentation of the outer surface of the cortex 
to direct one, but this seems to be a characteristic feature of the 
genus. 
Oinphalophloios White. The fossil now placed in Omphalophloios 
was originally described by Sternberg as Lepidodendron anglicum, 
and subsequently placed in Stigmaria by Brongniart. 
In Omphalophloios {Omphalophloios anglicus Sternb. sp., Plate 
LXIV., fig. 4) the cortex is divided into clearly-defined rhomboidal 
areas, Text Fig. 11, A.C.F., within which, and a short distance 
above the centre, is an elevated sub-cordate, or oval cushion, with a 
slightly raised, ring-like margin, Text Fig. 11, Bb, containing a little 
above its centre an oval scar with a single vascular cicatrice, Text 
Fig. 11, Be. Immediately below this upraised cushion, and attached 
as it were to its outer side, is a triangular ridge-like elevation 
containing a small pit, Text Fig. 11, Bd. 
Omphalophloios is probably the rhizome of one of the arborescent 
Lycopods, and is easily distinguished from Stigmaria on the one 
hand, and from Lepidodendron on the other, by the form of the 
vascular scar and cushion. This fossil is very rare in Britain, and 
has hitherto only been found in the Radstock series of the Upper Coal 
Measures of Somerset. 
Affinities of the Carboniferous Lycopods. I can here only 
summarise the conclusions arrived at as to the affinities of the various 
Carboniferous genera of Lycopods. To give all the evidence on which 
these opinions are based would too far extend the present paper. 
The genus Lycopodites is very closely related to the existing genera 
Lycopodium and Selaginella, and is probably their progenitor. Some 
botanists have even placed the members of the genus Lycopodites in 
Lycopodium, but we are scarcely warranted to take this course until 
we possess more definite knowledge of their fructification. 
