SPONDYLUS. 127 



the Trimingham Chalk appear to have the spines placed more closely together 

 than in other zones. The convexity of the valves varies considerably. Tlie 

 largest examples seen came from the B. mvcronata zone of Norwich and Shering- 

 ham. A few imperfect specimens obtained from the Chalk Marl of Folkestone 

 probably belong to this species. 



Types. — From the Senonian of Epernay, St. Sauveur, and Auxon. 



Distribution. — Cenomanian (Bed 11) of Maynard's Cliff, Sidmouth. Zone 

 of R. Cavieri of the Sussex coast. Zone of Terchrdtulina gracilis of St. Giles' 

 Pit, near Winchester, and Dover. Zone of H. planus of Twyford Down, near 

 Winchester, and Chapel Rock, Pinhay. Zone of M. ror-testtidivariuvi of Dover. 

 Zone of M. cor-anguimim of the Thanet coast, St. Margaret's, and the Sussex 

 coast. Uintacrinus -hand of Kingsgate (Margate). Zone of Marsupites of t]ie 

 Thanet and Sussex coasts. Zone of Actinocamax (jiiaiJratns of Hursley (Win- 

 chester), East and West Harnham (Salisbury), and the Sussex coast. Zone of 

 B. miicron.ata of Norwich, Sheringham, Clarendon (Salisbury), Ballard, and 

 Studland. Chalk of Trimingham. 



Spondtlus spinosus {Sowerhy), 1814. Plate XXIII, figs. 6 — 11 ; L'late 



XXIV, figs. 1—7. 



1814. Plagiostoma spinosa, J. Sotverhij. Miu. Couch., vol. i, p. 177, pi. Ixxviii, 



figs. 1—3. 

 y 1819. Spondtlus podopsideus, Lamarclc. Auirn. saus Vert., vol. vi, p. 194. 

 ? — Plagiostoma sulcata, Lamarclc. Ibid., p. 161. 

 1820. Peotinites aculeatus, E T. v. Schlotheim. Die Petrefactenkunde, p. 2-28. 

 1822. Plagiostoma spinosa, G. Mantell. Foss. S. Downs, p. 203, pi. xxvi, 



fig. 10. 



— — BRiGHTONiENSis, G. Mantell. Ibid., p. 204, pi. xxv, fig. 15. 



— — spinosa, a. Bromjniart. Descr. gt'ol. des Envir. de Paris, 



pp. 251, 320, 600, pi. iv, fig. 2. 

 1825. Pachttos spinosus, Defrance. Diet. Sciences uat., vol. xxxvii, p. 207, 



pi. Ixxviii, fig. 2 ; pi. Ixxix, fig. 1 . 

 ? — — striatus, Defrance. Ibid., p. 207. 



1827. Plagiostoma spinosum, S. Nilsson. Petrif. Suecana, p. 25. 

 1833, -_ _ S. Woodward. Geol. Norfolk, p. 40, pi. v, fig. 25 



(? young). 



1836. Spondtlus spinosus, A. Goldjuss. Petref. Germ., vol. ii, p. 95, pi. ev, 



fig. 5. 



— — DUPLicATUS, A. Goldfuss. Ibid., vol. ii, p. 95, pi. cv, fig. 6. 



1837. Plagiostoma spinosum, W. Hmingcr. Lethsea Suecica, p. 54, pi. \v, 



fig. 4. 



— Spondtlus spinosus, H. G. Bronn. Lethaea Geog., p. 684 (ed. 2), p. 280 



(vol. ii, pt. 5, ed. 3), pi. xxxii. fig. 6. 



