6 



FOSSIL MOLLUSCA OF THE CHALK. 



the specimen they represent was found in the Chalk near Ventnor, and is in the Cabinet of 

 Mr. S. H. Beckles. Fig. b shows the upper part of one side of ihe phragmacone apparently 

 complete ; the upper transverse lines are too sinuous to represent the edges of the septa, 

 M'hich, as far as we know them, are nearly horizontal. Perhaps, the lower parallel and 

 nearly horizontal lines may mark the edges of the septa, and the upper waving lines may 

 indicate the growth of the margin of the phragmacone, which seems to have been 

 furnished with two lateral processes. 



In fig. A, the cast displays very clearly the complicated groove running down the back 

 of the alveolar cavity. 



Fig. A 



Kg.B 



1. Belemnitella mxjcronata, ScJdotheim, Sp. Plate I, figs. 1, 2, and 3. 



Belemnites, r species : Breyn, de Belemnitis, figs. 1 — 6. 

 Belemnites mucronatus, Schlotheim. Petref., p. 47, No. 4. 



— — Mantell. Sussex, t. xvi, fig. 1. 



— — Nilsson. Petrif. Saec, t. ii, fig. 1. 



— — Sowerby. Min. Conch., t. 600, figs. 2 and 4. 

 Belemnites electrinus. Miller. Geol. Tr., 2d series, vol. ii, t. viii, figs. 18 — 21. 

 AcTiNOCAMAX VERUS? Miller. Loc. cit., t. ix, figs. 17 and 18. 

 Belemnitella mucronata, UOrbigny. Palseont. rran9. Terr. Cret., t. vii. 



— — Geol. of Russia and the Ural Mountains, vol. ii, t. xliii, 



figs. 1 and 4, not figs. 2 and 3. 



B. Testa suhcylindricd, impressionibus duabus vascularibus ramosis notatd, antice 

 fissuratd, postice obtusd mucronatd ; aperturd subrotundd ; alveolo conico excentrico. 



Shell elongated, subcylindrical, widening very slightly above, obtuse below, with a 

 distinct rounded point. Opening circular. Alveolus forming a regular hollow cone, with 

 a round base, and an apex of 18° to 20°, which is considerably nearer to the anterior than 

 to the posterior side of the shell ; the position of the septa may be faintly traced on the 

 lining of the alveolus. The fissure extends to within half an inch of the apex of the 

 cavity, but may be traced to the bottom, on the inside, by a continued depression ; another 



