PLATE IV. 



Fig. 1. — Myalina pemoides. A fragmentary specimen obtained from the Lower 

 Carboniferous Beds of Redesdale by Mr. John Dunn. My Collection. (Page 117.) 



Fig. 1 a. — The cast of the exterior of the same specimen, showing the surface 

 ornaments. (Page 117.) 



Fig. 2. — Myalina pemoides. The original of Portlock's Inoceramus pemoides, 

 now preserved in the Museum of Geological Survey, Jermyn Street. (Page 117.) 



Fig. 3. — Myalina Verneuilii. — The original of M'Coy's figure of Modiola 

 Verneuilii, preserved in the Griffith Collection of the Museum of Science and 

 Art, Dublin. (Page 115.) 



Fig. 4. — Myalina Verneuilii. The exterior of a right valve from the Lower 

 Carboniferous of Glasgow. Mr. J. Neilson's Collection. (Page 115.) 



Figs. 5, 5 a. — Myalina Verneuilii. Two views of a well-preserved specimen in the 

 Collection of the Geological Survey, Jermyn Street. (Page 115.) 



Figs. 6, 7, and 8. — Myalina Verneuilii. Three specimens from the Upper 

 Limestone series, Bankend, Lesmahagow. In the Braidwood Collection of 

 Dr. Hunter. (Page 115.) 



Fig. 9. — Myalina Flemingi. The original of M'Coy's Mytilus Flemingi, now 

 preserved in the Griffith Collection of the Museum of Science and Art, Dublin. 

 (Page 112.) 



Fig. 10. — Myalina Flemingi. A typical specimen from the Lower Carboniferous 

 of the neighbourhood of Glasgow. My Collection. (Page 112.) 



Fig. 10 a. — The same specimen viewed from behind. (Page 112.) 



Fig. 10 b. — The same specimen viewed from the front, showing the flat 

 anterior surface. (Page 112.) 



Fig. 11. — Myalina per alata. A cast of the left valve, showing all the details of 

 the interior. From the Mountain-limestone of Bolland. In the Collection of 

 the Geological Survey, Jermyn Street. (Page 119.) 



Fig. 12. — Myalina peralata. A specimen of a left valve from the Lower 

 Carboniferous Shales of Eskdale. My Collection. (Page 119.) 



Fig. 13. — Myalina lamellosa. Portion of a left valve from the Mountain- 

 limestone of Bolland. In the Collection of the Geological Survey, Jermyn Street. 

 (Page 124.) 



Figs. 14, 14 a, 14 b. — Myalina lamellosa. Three views of a specimen from the 

 same locality; in the same Collection. (Page 124.) 



Fig. 15. — Myalina sublamellosa. A left valve from the Lower Carboniferous of 

 Abden, Fife. My Collection. (Page 121.) 



