NEWTON : FOSSIL PEAEL-GEOWTHS. 139 



Inoeeramus. 



Senonian [Micraster cor-anguinum zone) : Northfleet, near Gravesend, Kent. 



Fig. 5. — An adherent pearl-structure on the inner surface of shell of Inoeeramus, 

 representing Morris's original specimen figured on pi. iv, fig. 12, of the 

 "Annals " for 1851. [British Museum, L. 20845.] 



Gryphcea dilatata, J. Sowerby. 



Kimeridgian (Drift) : Muswell Hill, near London. 



Fig. 6. — Interior of a lower valve, showing an elongate pearl-growth partially 

 adherent to the adductor muscular scar, taken from the original specimen in the 

 British Museum, which was figured by Morris in the "Annals" for 1851, 

 but without the whole of the valve, f nat. size. [British Museum, L. 21230.] 



Plate V. 



Inoeeramus labiaUis, Schlotheim. 



Turonian : Blue Bell Hill, Burham, Kent. 



Fig. 1. — Interior of a left valve, showing a part of its surface covered with small 

 pearly tubercles. [British Museum, L. 10384.] 



Inoeeramus. 

 Senonian : Charlton, Kent. 



Fig. 2. — Sectioned surface of a pyriform pearl-structure adherent to a fragment of 

 Inoeeramus, showing lateral extensions proceeding from the spherical portion of 

 the body. [British Museum, 44676.] 



Fig. 3. — A glass-section prepared from the same specimen (Fig. 2), showing the 

 concentric and radial details, x 2. 



Inoeeramus. 



Senonian : Northfleet, Kent. 



Fig. 4. — A glass section made from an isolated pearl-structure, showing the concentric 

 and radial characters, with an apparently cellular or prismatic nucleus, x 3. 

 In the collection of B. B. Woodward, Esq., F.L.S. 



Fig. 5. — An enlargement of the nuclear portion as seen in the same section, somewhat 

 resembling the central structure of a modern pearl as figured by Messrs. Herdraan 

 and HorneU on pi. i, fig. 14, of part v of their report, x 25. 



Inoeeramus. 



Senonian ; Northfleet, Kent. 



Fig. 6. — Section of an unattached pearl-like body of considerable size, showing the 

 concentric and radial structure, copied from Morris's original fig. 14 of the 

 " Annals " paper of 1851. 



Tenia oblonga, H. G. Seeley. 



Albian (" Cambridge Greensand ") : Cambridge. 



Fig. 7. — Natural cast of the interior of a left valve, exhibiting numerous rounded 

 cavities formed by pearl protuberances. [British Museum, L. 9062.] 



Note. — Unless mentioned to the contrary, the figures on the plates are represented 

 of the natural size. 



