132 GREY CHALK MARL. 



The specimens are marked with transverse lines of increase. 



The form of this shell resembles that of Conchyliolithus Anomites 

 sacculus of Martin*, but that species is more convex, and is destitute of 

 striae. 



Tab. XXV. figs. 7, 8. 12, exhibit a dorsal, front, and lateral view of the 

 same specimen. 



Locality. Hamsey : very rare. 



64. Terebratula squamosa. 



Longitudinally ovate, valves equally convex, surface squamous, margin 

 of the lower valve incumbent, beaks produced. 



Length 0*5 inch, width 0-4 inch; the greatest convexity of the united 

 valves, 0-3 incli. Both valves are equally gibbous ; the margin of the 

 lowermost is slightly incumbent, and surrounds the edge of the upper 

 valve. The lines of increase are numerous, concentric, and squamous. 

 The beak is a little produced, and has a circular aperture. 



The shells of the Terebratulee of the grey marl, are always in a good 

 state of preservation ; in the present species even some vestige of the 

 colour remains, the specimens being invariably of a bluish hue. 



Locality. Hamsey. 



G5. Inoceramus tenuis. 



Valves convex, marked with numerous fine concentric lines ; posterior 

 side depressed, small, lunulate ? hinge side short, expanded ; beaks convex, 

 incurved ; hinge oblique. 



The shell of this species is remarkably thin and fragile, and is marked 

 with numerous concentric lines produced by the lamellated structure of 

 the surface. The valves are regularly convex, and deepest in the middle. 



The posterior slope is smaU and lunulate ; the anterior, short and 

 expanded. The hinge is rather oblique. 



A few indistinct transverse undulations are observable in some ex- 

 amples. The specimens are usually about four inches long, and three 

 inches wide : the depth of the united valves 2-8 inches. 



* Petrificata Derhiensia, tab. 46. figs. 1, 2. 



