plants from the Devonian rocks 101 
beds at Plaistow, near Sherwell. A few examples are also in the 
Sedewick Museum, Cambridge. 
The figured specimen measures 21 cm. in length and 6°5 cm. in 
breadth. It is now known that Kvnorria is the cast of the inner 
surface of the outer cortex of a Paleozoic Lycopodiaceous stem. 
It is not however possible to identify the genus (e.g. Bothroden- 
dron, Lepidodendron, etc.) from such specimens, and there is 
perhaps little to be gained by distinguishing species of Knorria. 
We are not aware that precisely similar specimens have been 
already described from Devonian rocks, but these fossils are very 
common in Lower Carboniferous sediments in various parts of the 
world. Among these, Knorria imbricata, Sternb., and still more 
K. longifolia, Schimp.*, the latter from the Vosges, may be com- 
pared with the Devonshire specimens. 
It may be also mentioned here that although there are frag- 
ments of ridged casts in various collections, which recall portions 
of the internodes of Asterocalamites, we have not been able to 
satisfy ourselves that any real evidence of the occurrence of this 
genus.in Devonshire has as yet been found. It is a well-known 
fact that imperfect casts of Lycopods in the Knorria condition 
may be easily mistaken for pith casts of Asterocalamites. Many 
of the specimens described by Heer from the Devonian of Bear 
Island, and attributed by him to the latter genus, are in reality, as 
Nathorst has shown, to be referred to Bothrodendron. 
? Cordaites sp. 
Plate V, fig. 5. 
In the Townsend Hall collection in the Atheneum, Barnstaple, 
there is a fragment of a small leaf-like impression with parallel 
longitudinal striz. This is figured on Plate V, fig. 5, and to some 
degree it recalls the more slender Cordaitean Jeaves of the Carboni- 
ferous rocks. The specimen was derived from the Marwood beds 
at Plaistow. It measures however only 2:2 cm. in length and 7 mm. 
across, and is thus too fragmentary to be regarded as satisfactory 
| evidence of the occurrence of Cordaites in the Devonian of North 
Devon. 
This is the most satisfactory specimen which we have seen 
from this locality. Among other fragments, more obscure and 
indistinct, there is one from Plaistow (Plate V, fig. 7) in the 
Valpy collection (V. 10682) British Museum (Nat. Hist.) which 
has some resemblance to a cone and to a Lepidostrobus, but which 
is in reality too imperfect to merit description or determination. 
* Schimper, Terr. Trans. Vosges, 1862, pl. x1v. upper fig. ete. 
VOL, XVIII. PT. III, 8 
