PROSOllRAlifCHlATA.^CEBITnilUiE. 195 



Potamides ligatum, Edwards (MS.)- 



Horizon and Locality. 

 Oligocene. — Hempstead Beds. Hempstead. 



Potamides margaritse, Cossmau, 1889. 



Potamides margaritce. 



Ann. Soc. R. Mai. Belgique, 1889, vol. xxiv. pi. i. fig. 7, p. 67. 

 Horizon and Locality. 



Oligocene. — Headon Beds. Headon Hill. 



Potamides perditus, Bayan, 1870. 



Cerite tuhercule. 

 Ann. Mus. 1809, vol. 14. pi. 27. figs. 25, 26, p. 436. 



Cerithium Lamarchii. 

 Coq. Foss. Paris, 1833, vol. ii. pi. lix. figa. 27, 28, p. 410, non Brongniart. 



Cerithium deperditum. 

 Desc. Anim. sans Vert. 1864, vol. iii. p. 176, non Michelotti. 



Cerithimn perdifum. 

 Etudes Foss. Nouveaux, 1870, fasc. 1. p. 41. 



Horizon and Locality. 

 Oligocene. — Headon Beds. Headon. 



Potamides Sedgwicki, Morris, 1856. 



Cerithium Sedywicki. 

 Forbes's ' Isle of Wight,' Mem. Geol. Suit. 1856, pi. ii. fig. 12, p. 147. 



Horizon and Locality. 



Oligocene. — Hempstead Beds. Hempstead. 



Potamides semicoronatus, Lamarck, 1804. 



Cerithium semicoronatum. 

 Ann. Mus. 1804, vol. 3. p. 344. 

 Coq. Foss. Paris, 18.33, vol. ii. pi. 1. figs. 1, 2, p. 306. 

 Dixon's ' Sussex,' 1850, p. 182. 



Horizon and Locality. 



Middle Eocene. — Brachlesham Beds. Brook. 



Potamides submargaritaceus, Orbigny, 1850. 



Potamides Y maryaritaceus. 

 Mineral Conchology, 1822, pi. 339. fig. 4, non Brocchi. 



Cerithium submargaritaceum. 

 Prod. Paldont. 1850, vol. 2. p. 419. 



Cerithium elegans (non Deshayes). 

 Cerithium margaritaceum, var. 

 Forbes's ' Isle of Wight,' Mem. Geol. Surv. 1856, pi. ii. fig. 10, pi. iii. fig. 13, 

 pp.147, 1.50. 



Hm-izon and Locality. ^ 



Oligocene. — Hempstead Beds. Hempstead. 



o2 



