TAB. VI. 



Fig. 



22. Palaechinus Verneuiliana, King. Specimen, thrice the natural size, showing two 



rows of interambulacral plates. Humbleton Hill. 



23. — — Thrice the natural size. Tunstall Hill. 



24 (?) Muricated spine of probably PaldBchinus Verneuiliana. 



Humbleton Hill. Mr. G. Tate's specimen. 



25. Lingula Credneri, Geinitz. Specimen (twice the natural size) of the large valve. 



(This specimen shows the true form of the valve.) 

 Marl-slate, Thickley. 



26. — — Same valve as last, twice the natural size. Marl-slate, 



Thrishngton Gap. 



27. — — Small valve, twice the natural size. Marl-slate, Thrislington 



Gap. 



28. Discina speluncaria, ScMotkeim. Upper valve, a little enlarged, attached to a Pro- 



ductus horridus. Garmundsway. 



29. — — Under or attached valve, twice the natural size. Thris- 



lington Gap. 



30. Epithyris elongata, Schlotheim. 



Large valve, natural size, showing variations of 



the species. Specimens at figs. 30, 31, 32 



oo ) are casts from Humbleton Hill. Figs. 33, 34, 35 



represent testiferous specimens from Tunstall 



Hill. 



31. 

 32. 



34. — — 



35. — — 



36. — — Small valve of specimen at fig. 33. 



37. — — Small valve of a cast from Humbleton Hill. 



38. — — Lateral view of specimen at fig. 33, &c. 



39. — • — Lateral view of specimen at fig. 31. 



40. — — Lateral view of a testiferous specimen. Humbleton Hill. 



41. — — Umbonal view of a cast. Humbleton Hill. 



42. — — Frontal view of a specimen from Tunstall Hill. 



43. — — Frontal view of specimen at fig. 33, &c. 



44. — — Punctations of the shell, highly magnified, of specimen 



at fig. 42. 



45. — — View of the apophysary system, twice the natural size : 



«, loop ; h, crural base ; c, sockets ; c?, boss or cardinal 

 muscular fulcrum ; e, crura of the loop. Humbleton 

 Hill. 



(The letter h should have heen connected with the pointed part 

 proceeding from the centre of the hinge.) 



46. Cythere Geinitziana (X 15). 



