PLATE XXXI. 



N.B. 1. All figures on this plate are drawn from photographs. 



N.B. 2. All specimens are from my Collection unless otherwise stated. 



N.B. 3. All figures are magnified a little over two diameters except fig. 16. 



Fig. 



1. Trochus Sandersii, Tawney. Murchisonse-zone, Bradford Abbas. Back and 



front. (Page 370.) 



2. Trochus rupestris, sp. nov. Irony Nodule-bed (Murchisonge-zone), Burton 



Bradstock. Back. (Page 371.) 



3. Trochus sybilla, sp. nov. Op alinus -zone, Drympton. Back and front. 



(Page 371.) 



4. Trochus Wimooodi, Tawney, var. minor. Stoford {? Goncavus-bed). Back 



and front. (Page 372.) 



5. Trochus Winwoodi, Tawney, var. major. Goncavus-bed, Bradford Abbas. 



Back and front. (Page 372.) 



6. Trochus spiratus, d'Archiac. Lincolnshire Limestone, Weldon. Front and 



back. (Page 378.) 



7. Trochus spiratus, conical variety. Weldon. Back. N.B. — This specimen, 



like so many of the Weldon fossils, has suffered from attrition. 



8. Trochus dimidiatus, Sowerby. Parkinsoni-zone. Woolston. Front and back. 



(Page 379.) 



9. Trochus Zetes, d'Orbigny, as identified by Tawney. Gonca,vus-bed, Bradford 



Abbas. Back and front. (Page. 379.) 



10. Trochus duplicatus, Sowerby. Parkinsoni-zone, Burton Bradstock. Back 



and front. (Page. 373.) 



11. Trochus angulatus, Sowerby [? var. of T. duplicatus, Sow., cf. also T. Lorieri, 



d'Orb.]. Parkinsoni-zone, Burton Bradstock. Back and front. 

 (Page 374.) 



12. Trochus Duryanus, d'Orbigny. Parkinsoni-zone, Grove. Back and front. 



(Page 375.) 



13. Trochus sub duplicatus, d'Orbigny. Small form from the " Sands," Brims- 



combe. Back. (Page 375.) 



14. The same. Large form from the " Sands," Newton, near Yeovil. Front. 



15. " Trochus bicingendus," Lycett. Oolite Marl, Nails worth. Jermyn Street 



Museum. Back. (Page 389.) 



16. Trochus cf. Bixa, d'Orbigny. Base of the Lincolnshire Limestone, Lincoln. 



Front. X H. (Page 388 ) 



