PLATE XXIII. 



LOWER SILURIAN (CARADOC). 



Fig. 1. Asaphus {Basilicus) Marsioni, Salter. Natural size; 1 a, magnified. 



(5 Is a free cheek of a larger specimen. 

 Shales of Horderly. (Mr. H. W. 

 EdgelPs cabinet.) 

 Figs. 2 — 7. Asaphus {Basilicus) Powisii, Murchison. Chiefly from the Mus. of 



Pract. Geology. Figs. 3, 4, 6, are from 

 Mr. H. Wyatt Edgell's cabinet. 



2. „ „ „ Restored figure, from many specimens. The 



head is not so perfectly known, and is 

 only given here in outline. « Is a free 

 cheek from Mr. Edgell's cabinet. 



3. „ „ „ Tail of young specimen. (Mr. Griffith's 



cabinet.) 



4. „ „ „ Somewhat older. Horderly. 



5. „ „ „ Large specimen from Waterloo Bridge, 



Conway. (Mus. Pract. Geology.) 

 '6. „ ,, „ Labrum, not quite perfect at its base. 



7. „ ,, „ Specimen from Dinas Mowddwy, North 



Wales. (Mus. Pract. Geology.) 

 Figs. 8, 9. Asap/ms {Basi/icus i') /i^bridus, Salter. From the Caradoc Shales (called 



in the text " Llandeilo flags"?) Henllan 

 Amgoed, near Narberth, Carmarthenshire, 



