PLATE XIII. 
All the figures in this Plate are from specimens from Lummaton in my Collection, except where 
otherwise stated. 
SPIRIFERA INFIMA, n. sp. (Page 108.) 
Fie. 
1. Ventral view of a specimen with no signs of a sinus on the ventral valve, enlarged. 1 a, lateral 
view, showing the depth of the beak. 
2. Dorsal view of a typical specimen from this locality, showing the sharp cardinal angles and wide 
hinge-line, and a well-marked sinus, enlarged. 2a, lateral view. 
3. Dorsal view of a doubtful specimen with very rounded cardinal angles and little or no signs of 
any sinus, enlarged. 34a, lateral view. 
SPIRIFERA cuRVATA, Schlotheim, sp. (Page 107.) 
4. Dorsal view of a very narrow variety with a rather curiously shaped fold, enlarged. 4a, a 
ventral view. 
. Ventral view of a small shell of unusual shape, enlarged. 5a, lateral view showing the elevated 
hinge-line. 
at 
SPIRIFERA UNDIFERA, F. Rimer. (Page 105). 
6. Portion of the ornament of a specimen, showing the transverse ridges composed of rows of short 
lineations, and the linear riblets between the larger low ribs, x 7. 
7. Portion of the ornament of another specimen, in which the major ribs have vanished and the 
linear riblets have become more prominent, x 7. 
SPIRIFERA concINNA, Hall? (Page 105.) 
8. Dorsal view of a specimen retaining a portion of the surface, which is ernamented by fine unbroken 
rays instead of transverse ridges. 8a, portion of the surface showing these riblets, » 7. 
PENTAMERUS BREVIROSTRIS, Phillips, sp. (Page 120.) 
9. Specimen with an apparent but probably accidental area, labelled by Salter “ Spirifer, n. sp.” 
9a, front view. Wolborough. Vicary Collection. 
ATRYPA RETICULARIS, Linné, sp. (Page 114.) 
10. Specimen retaining several rows of very long fringes. 
ATRYPAP TRIGONELLA, Davidson. (Page 118.) 
11. Dorsal view of a decorticated specimen, enlarged. 
12. Dorsal view of another similar specimen, enlarged. 
ATRYPA DESQUAMATA, Sowerby. (Page 117.) 
13. Dorsal view of a young shell of the variety compressa, x 2°5 times. 
14. Dorsal view of another young shell of the same variety, but of very peculiar form, showing the 
dorsal sinus, enlarged. The shell being very thin, the marginal portions have been broken off. 
14a, side view much enlarged, showing the horizontal flatness of the foramen. 144, rear view, 
showing the shape of the area and the foramen, much enlarged. 
15. Dorsal view of a specimen, much enlarged, showing the thickening of the margin of the foramen. 
