EXPLANATION OF THE PLATES. Wi. 
Fig. 3.—OaGyer1a Bucuti, Brongniart. 
Siluria, third edition, 1859, pl. iii., figs. 1, 2,3; Memoirs Geological Sur- 
vey, Dec. 2, pl. vi., fig. 1. Mon. Brit. Trilob., p. 125, pl. xiv., figs. 1-7, 
and pl. xv., figs. 1-6. 
Reduced one-third from the figure in Decade 2, pl. vi., fig. 1, and British 
Trilobites, pl. xv., fig. 1, aided by specimens in Museum, Geological Sur- 
vey of Ireland, from Tre Coed, north of Builth. 
LLANDEILO Fiags only. ‘ It abounds in the distorted slates at Shelve and 
Hope Mill, Rorington, Middleton, and Meadowtown, Shropshire ; Builth, 
Radnorshire ; Llangadoe and Llandeilo, Caermarthenshire ; near Haver- 
fordwest, Musclewick Bay, Pembrokeshire; and Abereiddy Bay, Car- 
diganshire ; not hitherto found out of South Wales.” J. W. Salter, Mon. 
Brit. Trilob., p. 128. 
In examining the large collection of fossils made by the Geological Survey of 
Treland at Dunabrattin Head, Co. Waterford, the author believed he had 
correctly identified several of them with this very characteristic Trilobite : 
Mr. Salter, however, appears disposed to consider them to belong to a dis- 
tinct species. 
Fig. 4.—a, b. ZEGLINA BINODOSA, Salter. 
Siluria, third edition, p. 50; Foss. 8, fig. 6. Memoirs Geological Survey, 
Dec. 11, pl. iv., figs. 1-6 ; and vol. iii., p. 317, pl. xi. B, figs. 3, a-e. 
a. From Memoirs Geological Survey, vol. 111., pl. xi. B, fig. 3. 
b. From Decade 11, pl. iv., fig. 3 a, representing a portion of the eye, en- 
larged, which occupies nearly the whole cheek, as seen by the shaded 
part on one side of fig. 4 a. 
Lower LuanpErLo.—Abundant in black slate ; Cefn Gwynlle, in the district 
west of the Stiper stones, Shropshire. 
Fig. 5.—a, b. TRINUCLEUS FIMBRIATUS, Murchison. 
Siluria, third edition, p. 55; Foss. 10, fig. 6, and pl. iv., fig. 7; Geol. Surv., 
Dee. 7, p. 8. 
a. Original.—From a specimen in Museum, Geological Survey of Ireland. 
Locality.—Tre Coed, Builth, in black slates. 
b. Original, Portion of border or expansion of head, enlarged, from the same 
specimen. 
Uprrr LiuanpEILo.—“ Only yet found at Builth, in Radnorshire, It is exceed- 
ingly abundant in the lane leading to the farm-House, called Pen-cerrig, 
on the west side of the hill, where it occurs with Ampyx nudus and Ag- 
nostus M‘Coyjii.”” Dee. 7, p. 8. 
Fic. 6.—a, 6. Trrinuctevus Lioypu, Murchison. 
Siluria, third edition, p. 55; Foss. 10, fig. 7, and pl. iv., fig. 6; Geol. Surv., 
Decade 7, pl. vii. 
a. From Decade 7, pl. vii., fig. 1. 
b. Portion of border, or expansion of head, enlarged, from the same figure. 
LianpeILo Fiacs.— Abundant in Caermarthenshire, Dynevor Park, and 
Maerdy Bach, Llandeilo; Blaen-dyffryn-garn and Coed Sion quarries, 
D 
