46 EXPLANATION OF THE PLATES. 
PLATE XV. 
FOSSILS OF THE LLANDOVERY ROCKS. 
MOLLUSCA._BRACHIOPODA. 
Fic. 1.—a-d. PENTAMERUS OBLONGUS, Sowerby. 
planar Sree p- 641, pl. xix., fig. 10 (not fig. 12), P. Zevis, ibid., pl. xix., 
go, . 
ie oblongus, Brit. Sil. Brach., p. 151. 
a. Showing both valves. From Sil. Syst., pl. xix., fig. 10. 
b. Side view from the same figure. 
ec. Original. Internal cast of ventral valve; showing the “vertical median 
septum.” In dark grey sandstone ; from Tre Coed, Builth. Mus. G.S. I. 
d. Original. Internal cast of dorsal valve ; showing two similar long vertical 
septa; in Upper Llandovery sandstone, accompanied by Atrypa_hemi- 
spherica and Petraia elongata; from Nash Scar, Presteign. Mus. G. S. I. 
LLANDOVERY.—Sil., 4th ed., p. 527. “This species would appear to be 
restricted to the Cower and Upper Llandovery rocks, and to be very 
much more abundant in the last-named formation.” Brit. Sil. Brach., p. 
154. Amongst the Lower Llandovery localities may be mentioned Wrex- 
ham, Denbighshire ; Cefn, near Welshpool; also near Builth and Llan- 
dovery ; and in Upper Llandovery, at Nash Scar, Presteign ; Norbury, 
&e., in Shropshire, and Malvern; Pen-Cerrig, Builth; Llangadoc ; and 
near Haverfordwest. In Scotland it abounds in the yellow (Upper 
Llandovery) sandstone of Saugh Hill, and Penwhapple Glen; and other 
places near Girvan, Ayrshire. In Ireland, Professor M‘Coy mentions its 
occurrence in the (Llandovery) sandstone of Boocaun and Cappacorgue 
(where it is very abundant), Cong, Co. Galway ; chid., p. 154. 
Fic. 2.—PENTAMERUS UNDATUS, Sowerby, sp. 
Atrypa, Sil. Syst., p. 637. Pentamerus, Sil., 4th ed., pp. 90, 527, pl. viii., 
figs. 5, 6, 7; Brit. Sil. Brach., p. 155, pl. xix., figs. 4-9. 
Original. Internal casts. In Upper Llandovery sandstone, Penlan, Llan- 
dovery. Mus. G. S. I. 
Luanpovery.—Sil., 4th ed., p. 527. “Casts of this species occur abun- 
dantly in the Lower and Upper Llandovery, but especially in the former. 
Amongst the Lower Llandovery localities, it occurs near Welshpool, Llan- 
dovery, Builth, Haverfordwest, &e. In Upper Llandovery, at Man- 
dinam, and Penlan, Llandovery ; Builth, Llangadoc; Malverns; and 
Church Stretton. In Woolhope beds, at Buildwas.” Brit. Sil. Brach., 
p. 156. In. Ireland it has been collected by Mr, C. Galvan from Upper 
ap at Ballycar, Co. Clare, and near Cloonbur, Cong. 
us. G. 8. I. 
