SPONDYLUS. 125 



d'Orbigny/ differs from this species in liaving stronger ril^s at regular inter\'als, 

 and in being proportionately higher. 



N. asper, Goldfuss/ is simihxr in form, but the spines are coarser, fewer, ami 

 less regular. 



8. occidtus, Greinitz,^ is a very small (7 mm.) form, which may be closely related 

 to S. serratas, but the ribs appear to be more unequal and to bear tubercles which 

 are in contact, instead of spiny processes distinctly separated from one another. 



Remarks. — This is a very rare species ; I have seen only five examples which 

 could be definitely referred to it. 



Distribution. — Marsupites-zone (Utntacrinus-hed) of Devizes Road, near Salis- 

 bury, and the Thanet coast. 



Spondtlus Dutempleanus, (VOrbigny, 1847. Plate XXII, figs. 11a, h, 12a, Ij, ]'■■>, 



14 ; Plate XXIII, figs. 1—5. 



1833. DiANCHOEA spiNOSA, »S'. Woodivard. Geol. Norfolk, p. 48, pi. v, fig. 24. 

 1847. Spondylus Dutempleanus, A. d'Orbigny. Pal. rran9. Terr. Crt't., vol. iii, 



p. 672, pi. cccclx, figs. 6 — 11. 

 1850. — — — Prodr. de Pal., vol. ii, p. 2.54. 



1869. — — E. Favre. Moll. Foss. de la Craie de Lemberg, 



p. 159, pi. xiii, figs. 14, IT). 



1870. — — F. J. Pictet and G. Camplche. Foss. Terr. 



Cret. Ste. Croix (Mater. Pal. Suisse, 

 ser. 5), p. 262. 

 1887. — DuTEMPLEi, A. Pernn. Hist, du Terr, de Craie (Bull. Soc. 



Sci. hist, et nat. de I'Yonne, ser. 3, 

 vol. xii), p. 166. 

 1889. — Dutempleanus, E. Hohapfel. Die MoUusk. d. Aachen. 



Kreide. (Palseontographica, vol. xxxv), 

 p. 244, pi. xxvii, figs. 8 — 10. 



1891. — — J. Bohm. Die Kreidebild. des Fiirbergs, 



etc. (Palseontographica, vol. xxxviii), p. 88. 



1892. — E. Stolley. Die Kreide Schleswig-Holsteius 



(Mitth. a. d. Min. Inst. Kiel, vol. i), p. 236. 



Non 1875. — ?, A. J. Juhes-Browne. Quart. Jouru. Geol. 



Soc, vol. xxxi, p. 297. 



Descriptioth.—^\\e\\ oval, shghtly oblique, usually inflated, rounded ventrally, 

 pointed and produced in the umbonal region. Right valve sometimes with greater, 



» ' Pal. Fran9. Terr. Cret.,' vol. iii (1847), p. 671, pi. cccclx, figs 1—5. 

 2 ' Petref. Germ.,' vol. ii (1836), p. 96, pi. cvi, fig. 1. 



■5 "Das Elbthalgeb. in Sachsen" ('Palseontographica,' vol. xx, pt. 1), p. 207, pi. xlvi, fig. 1. 

 (N.B. — Enlarged about three times.) 



