PLATE XXIII. 



Fig. 1. — Lillia sulcata, S. Buckman. 



Fig. 1. — Part of the suture-line taken from the specimen depicted in Plate XXII, figs. 32, 33. 

 (Page 109.) 



Murchisonce-zone or Concavum-beds. 



Figs. 2 — 4. — Ludwigia (?) sp. 



Fig. 2. — Side view of a specimen from Clatcombe, near Sherborne, Dorset. In the Collection 

 of Mr. T. C. Maggs, F.Q-.S. (Page 107.) 



Fig. 3. — Front view of the same shell, showing slight ventral furrows. 

 Fig. 4. — Suture-line, taken from the same specimen. 



Sump hriesian um -zone. 

 Figs. 5, 6. — Sonninia (?) sp. 



Fig. 5. — Side view of a small specimen, differing in its ornamentation from the above and placed 

 here for comparison. From the "Ironshot" Oolite, Dundry Hill, Somerset. In the Collection of 

 the Bristol Museum. 



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



Figs. 7, 8. — Sonntnia sp. 



Fig. 7. — Side view of the specimen from which the suture-line, Plate XXII, fig. 34, was taken. 

 Springing from the middle of the sides of the inner whorls, and pressed tightly into, and almost hidden 

 by, the succeeding whorls, are small rudimentary spines. As they are not well preserved they are 

 easily overlooked, but such rudiments point to the probability of this specimen being a poorly- 

 developed form of the genus Sonninia. It is here figured because its suture-line was depicted where 

 that of Lillia sulcata should have been, and so that it may be compared with the other figures of that 

 species. From the "Ironshot" Oolite, Dundry Hill, Somerset. In the Collection ol the Bristol 

 Museum. 



Fig. 8. — Front view of the same specimen. 



Variabilis-suozone. 

 Figs. 9, 10. — Ludwigia sp. 



Fig. 9. — Side view of a specimen, without test. It is, in fact, little more than a cast in sand. 

 From bottom of Cotteswold Sands, Nadsworth, Gloucestershire. In the Collection of the late Mr. E. 

 Witchell. (Page 107.) 



Fig. 10. — Front view of the same specimen. 



Figs. 11 — 15. — Haugia variabilis {d'Orbigny). 



Fig. 11. — Side view, showing arcuate ribs. From White Lackington Park, near Ilminster, Somerset. 

 In the Collection of the Natural History Museum, South Kensington. This is the original specimen 

 of Ammonites jugosus, Sowerby, ' Min. Conch.,' pi. 92, fig. 1. But as neither Sowerby's figure nor his 

 description could possibly cause his species to be correctly identified, I deem it only an act of justice 

 not to supersede d'Orbigny's well-known name. (Page 146.) 



Fig. 12. — Front view of the same specimen. 



Fig. 13. — Suture-line taken from the same specimen. This was rather obscure, and the artist 

 experienced considerable difficulty in tracing it. 



Fig. 14. — Side view of a young specimen, showing the small umbilicus and the arcuate ribs. Cot- 

 teswold Sands, Coaley Wood, Gloucestershire (Bed 16). 



Fig. 15. — Front view of the same specimen. 



Figs. 16, 17. — Haugia Ogerieni (Dumortier). 



Fig. 16. — Side view of a specimen with its thin test partly preserved, showing subsigmoidal ribs. 

 Cotteswold Sands, North Nibley (Bed 18). 



Fig. 17. — Front view of the same specimen, showing much smaller carina (compare fig. 15). 



