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EOCENE MOLLUSCA. 



shells from that locality ; and I am strongly inclined to think that by one of those 

 accidents, which the greatest care will not always prevent, a shell from the Miocene 

 beds of Germany or Italy has been mixed with Hampshire fossils, and that thus an 

 erroneous locality has been given. The matrix, unfortunately, has been entirely 

 removed, and this evidence is not available. Under these circumstances, I retain 

 the species, for the present, as one of the English Eocene Pleurotomse, but with 

 much doubt. 



Size. — Axis, 1| inch ; diameter, 4-12ths of an inch. 

 Locality. — Muddiford ? 



No. 181. Pleurotoma nodulosa. Land. Tab. XXIX, fig. 7, a — c. 



Pleurotoma nodulosa. Lamk. 1804. Ann. du Mus., vol. iii, p. I/O, No. 18. 



— — — 1822. Histoire Naturelle, &c, vol. vii, p. 101, No. 25. 



— — Desk. 1824-37. Descr. des Coq. foss., &c, vol. ii, p. 466, 



t. 6.5, fig. 11—14. 



P. testa elongatd, fusiformi, undique spiraliter lineatd : spird elevatd, acuminata: 

 anfractibus ad hunter os angulatis, nodulosis ; lineis filiformibus, sub -regular ibus ; nodulis, 

 obtusis, crassis, obliquis : ultimo anfractu per-brevi, postice concavo, anlice depresso-convexo, 

 repente coarctato, in canali brevi, latiusculo, obliquo, terminanti : aperturd oblongo-ovali ; 

 labro tenue, aliforme ; sinu latiusculo, paullo prof undo, in margine collocato. 



Shell elongated, fusiform, having the whole surface covered with concentric raised 

 lines : spire pointed, produced, much exceeding the aperture in length ; whorls angulated 

 at the shoulders, where they present a series of blunt, thickish, rather oblong, tubercles, 

 somewhat distant from each other, very slightly oblique, and becoming feeble and 

 obscure on the last whorl ; the posterior margins are a little concave. The last whorl 

 is very short, flatly convex at the sides, contracted rather suddenly in front, and termi- 

 nates in a short, and somewhat wide canal. The spiral lines are thickish, rounded, 

 thread-like, equal, and nearly regular ; the aperture is of an oblong-oval shape ; the 

 outer lip thin, wing-like, projecting at the middle, and smooth within ; and the sinus, 

 which is placed in the margin, is rather wide, not very deep, and triangular in form. 



Lamarck describes the concentric lines which ornament the French shells as very 

 thin ; while in the English specimens the lineation is strong and coarse. This 

 difference in the character of the sculpture on the Eocene shells of the two countries is 

 not of unfrequent occurrence, and may be attributed to outward conditions only. 

 The sinus in the outer lip is described by Deshayes as being " narrow and deep 

 but in a series of specimens from Grignon, for which I am indebted to that gentle- 

 man, the sinus corresponds pretty closely with that found in the English specimens. 



