PLATE XXX. 



Opalinum-zone (Moorei-beds). 



Figs. 1, 2. — Grammoceras pluitans (Dumortier). 



Fig. 1. — Side view of a specimen with well-preserved test, showing irregular 

 ribs, sometimes closely approximate or sometimes united at the inner margin. 

 Frocester Hill (Coaley Peak). My Collection. (Page 190.) 



Fig. 2.— Front view of the same specimen showing the squareness of the aper- 

 ture. 



Figs. 3 — 7. — Grammoceras mactra (Dumortier). 



Fig. 3. — Side view of a specimen with well-preserved test, showing the ribs 

 strongly projected on the ventral area (var. y). The coarse ribs of the inner whorls 

 have not been clearly depicted, while the irregular ribs are too prominent. Buck- 

 holt Wood. My Collection. (Page 176.) 



Fig. 4. — Front view of the same specimen. 



Fig. 5. — Side view of a variety in which the distant ribs last until a later period 

 of life (var. S). The ribs on the top of the whorl are not projected enough towards 

 the front. Frocester Hill (Coaley Peak). My Collection. 



Fig. 6. — Front view of the same specimen. 



Fig. 7. — Suture-line of the same specimen. 



Figs. 8 — 10. — Grammoceras lotharingicum (Branco). 



Fig. 8. — Side view of a specimen not preserved as well as could be wished, 

 especially the inner whorls ; the test is present. North Nibley, Gloucestershire 

 (Bed 6, Section vii, p. 46). My Collection. (Page 199.) 



Fig. 9. — Front view of the same specimen. 



Fig. 10 — Side view of a smaller specimen, perhaps a variety of the above 

 form. North Nibley. My Collection. 



Figs. 11 — 14. — Grammoceras subcomptum (Branco). 



Fig. 11. — Side view of a specimen without test. Haresfield Hill. My Collection. 

 Fig. 12. — Front view of the same. (Page 198.) 



Fig. 13. — Side view of a specimen with the ventral lappet of the mouth. Hares- 

 field Hill. My Collection. 



Fig. 14. — Back view of the same specimen to show the ventral lappet. 



Figs. 15 — 17 and 19. — Dumortieria Moorei (Lycett). 



Fig. 15. — Side view of a specimen to compare with fig. 3. From the Yeovil 

 Sands, Bradford Abbas, Dorset. My Collection. 



Fig. 16. — Front view of the same specimen. 



Fig. 17. — Suture-line of the same specimen to compare with fig. 7. The 

 smaller inferior lateral lobe and the drooping inner part of the suture-line are the 

 distinctions. (Page 162.) 



Fig. 19. — Portion of a specimen to show the mouth-border. Buckholt Wood. 

 My Collection. 



Fig. 18. — Dumortieria radiosa (Seebach). 



Fig. 18. — Side view of a specimen with well-preserved test showing straightness 

 of the ribs on the lateral area, and their little projection ventrally. Frocester 

 Hill (Coaley Peak). My Collection. 



