MIDDLE BALA GROUP. 

Case and 
Column of 
Drawers. 
Reference to McCoy’s 
Synopsis: and Figures of Genera. 
43 

Names and References; Observations, &c. 
Localities and Numbers. 

Gk 
Gk 
Gk 
Gk 
Gk 
Caninia, p. 28. 
(Strephodes, p. 30). 
PAL AL (eh sates, (0); 
Sarcinula, p. 37. 

p. 39. 
Pl. 1 B, fig. 23, 24. 

Petraia. 
p. 40. 
p. 40. 
Pl. 18, fig. 26, p. 40. 



Omphyma turbinata var. 
Omphyma turbinata, (or perhaps Cyathophyl- 
lum). 
Cyathophyllum Craigense, McCoy. (The twist- 
ing of the lamellee at the base of the cup is 
not uncommon in Cyathophyllum, and 
Strephodes.) 
Sarcinula (Syringophyllum) organum, Linn. sp. 
(Mon. Brit. Fos. Cor. pl. 71, fig. 3). One 
of the most frequent fossils in Sweden, and 
Norway, in the slate rocks. 
Petraia equisulcata, McCoy. The genus Pe- 
traia is eminently Silurian and Devonian: 
and is but rare in Cambrian rocks—except 
their upper members. Its metropolis is 
the May Hill Sandstone. Like Cyathophyl- 
lum in all respects except habit, for the cup 
is always very deep, and the tabule so 
twisted and matted, as to form a solid base. 
Hence, in casts the solid base disappear- 
ing—a cavity is left in the stone: in the cup 
portion, the matrix assumes the shape of a 
grooved and striated pyramid, truncated ab- 
ruptly. The species are numerous, and not 
yet thoroughly made out. 
N.B. P. wquisulcata has the septa more regu- 
lar than usual in the genus. 
Petraia elongata, Phill. (Pal. foss. Cornwall 
and Devon. t. 2, fig. 6 B), Bala. 
Petraia rugosa, Phill. (id. t. 2, fig. 7). 
Petraia subduplicata, McCoy. An extremely 
frequent fossil in the Upper Bala (Llan- 
dovery) rocks and easily distinguished by its 
regular form and crenulated septa. (P. ziczac 
McCoy, Sil. foss. Ireland, p. 60, appears to 
be the same.) 


Coniston. 
Coniston. 
a. 100, Craig Head, Gir- 
van. 
Coniston Water. 
Sleddale. 
High Haume. 
Long- 
Coniston; Bala. 
Bala. 
a. 204, Penarth, Meifod, 
on the same tablet with 
P. subduplicata in the Llan- 
dovery collection (end 
case). 
Llansantfraid, Glyn Cei- 
riog. 
