TABLE V. 



LOWER SILURIAN. 

 FIG. 



1. Cheirurus bimucronatus, Murch. Large internal cast from Caradoc Strata, 



Skoleshook, Pembrokeshire, also figured in Me- 

 moirs of Geof Survey, vol. ii, pt. 1, pi. vii, fig. 4. 

 (Mus. Pract. Geol.) 



2. ,, ,, ,, . Smaller head, external surface, Caradoc 



Strata, Chair of Kildare. (Mus. Pract. Geol.) 



3. ,, „ ,, Young. May Hill Sandstone of Norbury. 



(Mr. W. Edgell's cabinet.) 



4. „ ,, ,, Young, distorted {Ceraurus Willianmi, 



McCoy, figured specimen), Llandovery Rock, 

 Llandovery. (Woodw. Mus.) 



5. „ ,, ,, Labrum of large specimen, Chair of Kil- 



dare. (Mus. Pract. Geol.) 

 6 — 8. „ gelasinosus, Portlock. Fig. 6, tolerably perfect surface of 



Ayrshire specimen. (Mus. Pract. Geol.) 

 Tigs. 7, 8, Portlock's figured specimens from 

 Tyrone. Both are Caradoc localities. 

 9 — 12. „ juvenis, Salter. Fig. 9, exterior of glabella, Chair of Kildare. 



Fig. 10, internal cast, Sholeshook, Pembrokeshire. Fig. 

 11, side view of same. Fig. 12, tail from Chair of 

 Kildare. Caradoc Beds. (All from Mus. Pract. Geol.) 



13. „ octolobatus, McCoy. Caradoc of Penwhapple, Ayrshire. (Brit. Mus.) 



14. „ „ The same, tail from Rhiwlas, Bala. (Mus. Pract. Geol.) 



(Probably this is the C. clavifrons, Dalman ; C. affinis, 

 Angelin.) 



15. ,, cancrurus, Salter. Originally described specimen, from the Chair 



of Kildare. (Mus. Pract. Geol.) 



16. „ „ ? Chair of Kildare. (Sir. R. Griffith's coll.) 



17. „ Sedgwicki, McCoy. Llandeilo Flags of Builth. (Woodwardian 



Museum.) 

 18 — 20. ,, Frederici, Salter. Upper Tremadoc Slate of Portmadoc, N. 



Wales. (Fig. 18, Mr. D. Homfray's cabinet. Fig. 

 19, Mr. Ash's cabinet. Fig. 20, Mus. Pract. Geol.) 

 21. „ Frederici?, variety. Same formation and locality, Garth Hill, Port- 



madoc. (Mr. D. Homfray's cabinet.) 



