
Case and 
Column of 
Drawers. 

G 
case 
case 
Gk 
Gk 
Gk 
Gk 

Reference to McCov’s 
Synopsis: and Figures of Genera. 
LOWER BALA GROUP. 

Names and References; Observations, &c. 

Worms continued. 
p. 129. 
Bivalve Crustacea. 
Pl. 11, f. 2 (Cytheropsis). 
00 
0 
Beyrichia, Pl. 1, £. 3, p. 136. 
Trilobites. 
Diplorrhina triplicata. 
Syn. Pl. 18, f. 11, p. 142 
oO 
ANUS, 
(T. gibbifrons and T. Caractact 
in part, pp. 144, 5.) 




Nereites Cambrensis, McLeay, (Sil. Syst. t. 27, 
fig. 1). It isa mistake to represent this as 
a very long worm. Its trails are visible for 
some length: four or five individuals on the 
slab having traversed some space (marked 
by a simple line) and been imbedded at the 
end of their trail. In one case the worm 
has again retreated, before death, along the 
line made by his track. 
Crustacea. Phyllopods and Trilobites:— 
No higher orders than bivalved and Apus-like 
Entomostraca, with Trilobites, have been 
detected in any beds beneath the May Hill 
Sandstone. 
Cythere (Cytheropsis) Aldensis, McCoy. A mi- 
nute smooth bivalve shell, slightly curved. 
Such species are abundant everywhere; and 
have been mostly left for description to 
Prof. R, Jones. 
Primitia, one or two species (Prof. R. Jones). 
Beyrichia complicata, Salter, Mem. Geol. Surv. 
Vol. 11. pt. 1, pl. 8. fig. 16, p. 295, Vol. m1. pl. 
19, fig. 9. Beyrichie are bivalved Crustacea, 
with lobed and furrowed carapaces. 
Trilobita. 
Agnostus MacCoyii, Salter. Decades Geol.Surv. 
x1. pl. 1, figs. 6, 7. Mem. Geol. Surv. Vol. 111. 
p.297, pl. 13, fig.8. Very common in Llandeilo 
flag. Only generally, not minutely like the 
Bohemian species figured by Barrande and 
Corda, Agnostusisthe simplest of all trilobites. 

Agnostus 
to determine. 
, Sp. not quite perfect enough 
Trinucleus favus, Salter (Mem. Geol. Surv. Vol. 
ll. p. 320, pl. 13, fig. 9). This is distin- 
guished by the square form and honeycomb- 
structure of the fringe, the outer cells being 
largest;—like those of drone-cells in a comb. 
31 
Numbers and Localities. 
a.'72*, Llampeter, S. Wales, 
the figured specimen. Pro- 
bably Middle Bala. The 
rolling system of S. Wales 
consists, as we now know, 
of Upper and Middle Bala 
rocks, 
a. 77, Aldeans Limestone. 
Stinchar River. a. 77%, 
Lower Caradoc Shales, 
Shineton, Buildwas, 
Lower Shales, Shineton, 
near Buildwas, Shropshire. 
Pont-y-meibion, Llanarmon, 
N. Wales (coll. by Prof. 
Sedgwick and J. W. Salter, 
1842). 
a. 86, Pen Cerrig, N. of 
Builth. It occurs every- 
where, but sparingly in 8. 
Wales, in these rocks. 
Shineton, Buildwas. 
a. 980, Llandeilo. Pres. by 
Mr. T. McK. Hughes. From 
Tregib, and Golden Grove, 
Llandeilo. (McCoy has la- 
belled some of these 7. 
gibbifrons). Craig-y-beri, 
Llanarmon fach. 
