INOCERAMUS. 307 



INOCERAMTJS UNDTJLATO-JM.ICA'JTS nir. DIGJTATVS, ScMuter, 1877. r J\ .X t-fl ^. 62. 



1873. Inoceramus digitatus, F. Schmidt. Mem. Acad. Imp. Sci. de St. Pe'tersb., 



ser. 7, vol. xix, no. 3, p. 25 (partim), 

 pi. vi, figs. 3, 5. 



1877. — (7. Schliiter. Palaeontograpbica, vol. xxiv, p. 2(>7, 



pi. xxxvi. 



1878. — C. Barrois. Ann. Sou. guul. dn Nord, vol. v, 



p. 475. 

 1902. — — A. Wollemann. Liineburg. Kreide (Abhandl. d. 



k. preuss. geol. Landesanst., 

 n.f., 37), p. 70. 



Remarks. — As was pointed out by Schliiter, this form is very closely allied to, and 

 perhaps not separable from, f. undidaio-plicatus ; it differs from the latter mainly 

 in that the posterior ribs are stronger and fewer in number than the anterior ribs, 

 but the early parts of the shell are very similar in the two forms. Until more 

 specimens have been obtained the exact relationships of the two forms cannot be 

 determined, and for the present it seems best to regard I. digitatus of Schliiter 

 (non Sowerby) as a variety of I. undulato-plicatus. 



Distribution. — Zone of Micraster cor-anguinwm of Charlton, Snowdown Colliery 

 Shaft, Nonington near Dover, Preston near Faversham, and Salisbury. Zone of 

 Actinocamax quadrat us of Salisbury. 



Inocekamlis Lamakcki, Parkinson, 1819. Plate LII, figs. 4 — 6; Plate LIII, figs. 



1—7. Text-figs. 63—85. 



1768. Ostreopinnites, J". E. I. Walch. Naturgeschichte d. Verstein., vol. ii, 



p. 142, pi. di**, figs. 1 — 5. 

 1819. Inoceramus Lamarckii, /. Parkinson. Trans. Greol. Soc, ser. 1, vol. v, 



p. 55, pi. i, fig. 3. 

 1822. — Ctjvieri, /. Sowerby. Trans. Linn. Soc, vol. xiii, p. 453, 



pi. xxv. 



— Lamarckii, G. Mantell. Foss. S. Downs, p. 214, pi. xxvii, 



fig. 1. 

 — Cuvieri, Mantell. Ibid., p. 213, pi. xxvii, fig. 4, pi. xxviii, 



figs. 1, 4. 



— Brongniarti, Mantell. Ibid., p. 214, pi. xxvii, fig. 8. 

 Websteri, Mantell. Ibid., p. 216, pi. xxvii, fig. 2. 



— — undulatus, Mantell. Ibid., p. 217, pi. xxvii, fig. 6. 

 — - latus, Mantdl. Ibid., p. 216, pi. xxvii, fig. 10. 



— Catillus Cuvieri, A. Brongniart. In Cuvier's Ossemens Foss., vol. ii,. 



p. 601, pi. iv., fig. 10. 



