PLATE XX. 



Athryis (Cleiothyris) Koyssii, Leveille, sp. (Page 148.) 

 Fig. 



1. Portion of the mould of a specimen, showing the spines, x 8. Poleshill ? Porter Collection. 



2. Portion of the mould of another specimen, showing the transverse ridges and the commencement 



of the spines, x 8. Pilton. Porter Collection. 



Rhynchonella laticosta, Phillips, sp. (Page 164.) 



3. Large obliquely distorted specimen. 3«. Another view. Laticosta Cave, Baggy. My Collec- 



tion. 



4. Cast of a smaller dorsal valve, showing the median septum. Laticosta Cave, Baggy. My Collec- 



tion. 



Strophomena rhomboidalis, Wilckens, sp. (Page 168.) 



5. Interior of a dorsal valve. Pilton. Porter Collection. 



Orthis interlineata, Sowerby. (Page 165.) 



6. Cast of a dorsal valve, x 2. Pilton. Porter Collection. 



7. Cast of a ventral valve, x 2. Pilton. Porter Collection. 



Orthis, sp. (Page 165.) 



8. Specimen, drawn from a wax cast of a mould, x 6. So, Portion of shell, x 30, showing markings, 



which may, however, be partly due to weathering. Saunton ? Porter Collection. 



9. Specimen, x 6. Saunton ? Miss Partridge's Collection. (The slab on which this lies proves to 



be the reverse of the slab in the Porter Collection ; it contains several small specimens, and the 

 ' artist appears to have chosen the cast of the same shell as that in the last figure.) 



Orthotetes crenistria (Phillips), var. arachnoidea, Phillips. (Page 166.) 



10. Portion of a large variety, with very fine and numerous ribs, x 2. " Blagiford Paper Mills," 



Ilfracombe Boad. Porter Collection. 



11. Portion of another specimen, with few and coarse ribs, x 2. Saunton Down, south end of Croyde 



Bay. Hamling Collection. 



Productus pr^elongus, Sowerby, sp. (Page 168.) 



12. Dorsal valve, showing the median rib and the ears, x §-. 12 a, side view, x § . Top Orchard, 



Barnstaple Athenaeum. 



13. Small ventral valve, showing the scars of spines in the sinus and on the ears, x 2. 13 a, side 



view, X 2. Pilton. Porter Collection. 



Productus pr^longus, var. siaiplicior, n. var. (Page 169.) 



14. Specimen partially hid by matrix, showing the absence of a median sinus, and the presence of 



short scattered spines, x 2. 14 a, portion of shell enlarged. Poleshill. Poi'ter Collection. 



15. Another specimen, with smaller umbo, X 2. 15 a, side view, x 2. Barnstaple. Woodwardian 



Museum. 



Productus scabriculus, Martin, sp. (Page 170.) 



16. A transverse ventral valve, nat. size. Smoking House Lane. Porter Collection. 



17. Another distorted specimen, with scars of spines on the ears. Woodwardian Museum. 



18. Portion of mould of dorsal valve, x 10. Pilton. Porter Collection. 



