PLATE LI. 



CARBONIFEROUS SPECIES. 



{Supplementary illustrations.) 



Fig. 

 1, 2. Productus sub-lavis. From the Carboniferous limestone of Clitheroe, in 



Lancashire. Fig. 1 in the collection of Mr. J. 

 Parker, of Manchester. 

 3. Betzia or Rhynchospira Carbonaria, Dav. From the lower black Carboni- 



ferous shales of Skrinkle, Pem- 

 brokeshire, and Museum of Prac- 

 tical Geology. 

 4 — 9. Retzia radialis, Phillips. Various modifications in shape. From Yorkshire, 



Derbyshire, and Scotland. 

 10. „ ? Uncertain form. From Derbyshire. 



11 — 13. d{//y?-is_plano-sulcala,~P\u\\\])S. Specimens distorted by pressure and cleavage. 



From the Carboniferous limestone of Cork. 

 Fig. 11 is the original specimen from which 

 M' Coy's A. viryoides of the ' Synopsis' was 

 created, now in the collection of Mr. J. Wright, 

 of Cork. Fig. 13 shows portions of the fringe. 



14. Athyris lamellosa, L'Eveile. With portions of its fringe-like expansions. From 



the Carboniferous limestone of Little Island, 

 Cork, Ireland. 



15. Spirifera lineafa, Martin. Showing the manner in which the rows of spines 



succeed each other over the surface of the valves. 

 15 fl> portion enlarged. From the Carboniferous 

 shales of West Broadstone, near Beith, Ayrshire. 

 10. ,, Urii. Natural size, showing its spiny investment. Fig. 10"' a por- 



tion enlarged. Hill Head, Lanarkshire. 



17. Cyrtina septosa, Phillips. The shell being removed from the dorsal valve, 



shows upon the internal cast the impression of 

 the posterior (a) and anterior (a') adductor muscles. 

 From Settle, Yorkshire. 



18. ,, ,, A very transverse young specimen. From Wetton, in Staf- 



fordshire. 



