Chap. IV.] 
CAEADOC FOSSILS. 
69 
hillocks of this formation between Chnrch Stretton and Marsh-Brook. 
These rocks consist of purple and red earthy sandstones, in parts micaceous, 
with partings of green earth, some courses of the shelly beds or ' Jacob's 
Stones,' and brown calciferous grits. Near Church Stretton the rock is 
earthy and incoherent, and in it is Diplograpsus pristis, Poss. 12. f. 4, a 
common Lower Silurian Graptolite, which occurs in the Bala schists in 
many parts of Wales. This variety of the sandstone is concretionary, ex- 
foliates into balls on weathering, and is full of irregular joints, the surfaces 
of which are coated with a film of the indigo-coloured oxide of iron so 
common in the Ludlow rocks. 
Others of the fossils which abound in the Caradoc beds are represented 
by woodcuts in the Chapter IX., and in Plates IY. to VII. of this work ; 
the latter are reprints of the figures published as original Caradoc types 
from this district. Among them, the geologist who may have explored 
Worth Wales will perceive the fossils which occur in many parts of that 
region, including the casts of Brachiopods he may have collected near 
the summit of Snowdon. 
In the lists of fossils given in the memoir by Salter and Aveline on the Ca- 
radoc Sandstone (Journ. Geol. Soc. Lond. vol. x. p. 62), we find that Trinu- 
cleus concentricus ranges from the lowest to the highest beds. The Hoar Edge 
grits contain Phacops apiculatus, Salter, Homalonotus rudis, id., Beyrichia com- 
plicata, id., Orthis Actonise, 0. flabellulum, O. vespertilio, 0. testudinaria, and 
0. calligramma, most of these being species described in the ' Silurian System ' 
as typical of the Caradoc formation. With them, however, is associated the 
Calymene Blumenbachii, so common in the Upper Silurian division. 
Two Trilobites, highly characteristic of this zone, whether in Shrop- 
shire or in North and South Wales, which were omitted in the first edi- 
tion of this work, are given in this 
woodcut. Trinucleus seticornis, Hi- 
singer (f. 1, 2), is found wherever 
the Caradoc rocks take on a calca- 
reous or shaly character. Phacops 
apiculatus, Salter (f. 3), on the other 
hand, was a denizen of sandy sub- 
marine ground, and is plentiful in the sandstones of Shropshire and North 
Wales. 
The following fossils were found by Mr. Randall, on the banks of the Cownd 
Brook, in the Lower Caradoc beds as they range towards the Wrekin : — Diplo- 
grapsus pristis ; D. foliaceus ; Orthis calligramma ; O. testudinaria ; Disema ; 
Lingula attenuata ; Palsearca elongata ; Orthonota nasuta ; Ctenodonta varicosa ; 
Theca triangularis ; Euomphalus j Orthoceras j Beyrichia complicata ; Trinucleus 
concentricus. 
Ascending to the higher strata through courses of the freestone above noticed, 
in which some of the same Orthidae occur with other forms, we reach the thin- 
bedded ' Cheney Longville flags ' of my earlier sections. At one or two localities 
Caradoc Trilobites (14). 
3 
