• PLATE IV. 
Myalina LUNA, n. sp. (Page 48.) 
Pig. 
1. Left valve, showing the small subterminal umbo and the concave anterior side. 
Lummaton. Mj Collection. 
HoPLOMYTiLUS OEASSUS, Sandbergev. (Page 44.) 
2. Upper portion of a flatfish right valve apparently with surface much worn, 
showing the acute terminal umbo. 2 a, inner view. Wolborough. 
Museum of Practical Geology. 
3. Inner view of another, much worn specimen. 3 a, anterior view. Wol- 
borough. Woodwardian Museum. 
Myalina pinnoides, WJiidborne, sp. (Page 49.) 
4. Internal cast of right valve, showing median depression. Wolborough. 
Vicary Collection. 
MoDioLOPSis POLiTA, WMdhome, sp. (Page 42.) 
5. Left valve, showing the small anterior lobe and the great transverseness of 
the shell. Barton (?). Torquay Museum. 
GossELETiA (?), sp. (Page 50.) 
6. Portion of right valve, very deep anteriorly. 6 a, portion of surface X 3. 
Lummaton. My Collection. 
MoDiOLOPSis, sp. (Page 43.) 
7. Posterior part of a very transverse left valve, showing ornamentation. 
Wolborough. Vicary Collection. 
PosiDONOMYA OBLONGA, Trenkuer, sp. (Page 53.) 
8. Right valve, showing the small central umbo, the flat triangular wings, and 
the distant acute ridges. Wolborough. Torquay Museum. 
RuTOTiA ELLiPTiCA, WMdbome, sp. (Page 55.) 
9. Right valve of a small broad specimen. 9 a, anterior view. Lummaton. 
My Collection. 
10. Left valve of another small specimen. Lummaton. My Collection. 
Ptbeinea bbllula, Whidborne. (Page 57.) 
11. Left valve of a defective specimen, partially retaining the shell. Wolborough. 
Museum of Practical Geology. 
