18 EXPLANATION OF THE PLATES. 
Llangadock ; frequent in Shropshire, Middleton, and the country about 
Cherbury and Shelve.” Dec. 7, description of pl. vil., pp. 1 and 4. 
Fig. 7.—a, b,c. AMPYX NUDUS, Murchison, sp. 
Siluria, third edition, p. 225; Foss. 46, fig. 7, aud pl. iv., figs. 9, 10. 
Memoirs Geological Survey, Decade 2, pl. x. 
a. From the original figure by the author, in the above Decade, fig. 1, aided 
by specimens from Pen Cerrig, Builth, in Museum Geological Survey, 
Treland. 
b,c. Original. Young dislocated specimens, showing commencement of spines ; 
from the same locality and Museum. 
Fig. 8..-CALYMENE DUPLICATA, Murchison. 
Siluria, third edition, p. 55; Foss. 10, fig. 10, and pl. iii., fig. 6; Memoirs 
Geological Survey, vol. ii., part 1, p. 236; and vol. iii., p. 327, pl. xvii, 
figs. 15-20; Mon. Brit. Trilob., p. 100, pl. ix., figs. 19-24. 
LuanbDEILo Fracs.—Near Shelve, and Wilmington, Shropshire ; Builth, Rad- 
norshire, abundant; Lann Mill, near Narberth, Abereiddy Bay, Pem.. 
brokeshire, abundant. 
