PLATE XX. 



ATHBYIS (CLEIOTHYBIS) EOYSSII, 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. 



KHYNCHONELLA LATICOSTA, Phillips, sp. (Page 164.) 



3. Large obliquely distorted specimen. 3 a. 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. 



STBOPHOMENA EHOMBOIDALIS, Wilckens, sp. (Page 168.) 



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



OBTHIS INTEELINEATA, 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. 



OBTHIS, sp. (Page 165.) 



8. Specimen, drawn from a wax cast of a mould, X 6. 8 a, 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.) 



OETHOTETES CEENISTEIA (Phillips), var. AEACHNOIDEA, Phillips. (Page 166.) 



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



Ilfracombe Eoad. Porter Collection. 



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



Bay. Hamling Collection. 



PBODTJCTUS PRJGLONGUS, Sowerby, sp. (Page 168.) 



12. Dorsal valve, showing the median rib and the ears, X f . 12 a, side view, X f . 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. 



PBODUCTUS PB^LONGUS, var. SIMPLICIOB, 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. Porter Collection. 



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



Museum. 



PBODUCTUS SCABBICULUS, 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. 



