PLATE 6. 



Page 



Fig. 1, 2, 3. Brachiocrinus nodosakids. 118 



1. The inner side of an arm with tentacles attaelied, showing on the right side one at unequal 

 distance from the others. 



2 k 2 a. Inner side of the base of an arm inciuding the first three joints, with points of at- 



tacliment for the tentacles, and the same enlarged. 



3. Exterior surface of the same enlarged. 



3 a. Transverse section, showing the form of the arm-joints. 



Fig. 4, 5, 6. CoEONocEiNus polydactylus. 124 



4. Lateral view of a fragment of the upper part of the body and bases of the arms. 



5. View of the summit, showing its structure and the origin of the arms. 



6. Enlargement of some plates of the summit. 



Fig. 7 - 15. Columns of undetermined Crinoide^. 125 



7, 8, 9 & 10. Fragments of pentagonal columns, bearing nodes at the angles, which seem to 

 have been the bases of little branchlets. 



11, 12 & 13. Sections of pentagonal columns, showing varying degrees of angularity, till in 

 the last one the angles project in wing-like expansions. 



14. Fragment of Lower Pentamerus limestone, with pieces of columns of two or more species. 



15. Section of a pentagonal column, showing marks of longitudinal division at the angles. 



Fig. 16 - 21. Tentaculites elonoatus. 13(5 



16. An individual of medium size. 



17. An individual of about the same Icngtli as the preceding, slightly compressed below, 

 giving it an apparently greater breadth at the base. 



18. A large individual having a length of three inches. On one side of the base, the greater 

 distance between the annulations shows the interior structure with more elongate inter- 

 nodes. 



19. Enlargement of a portion, showing the strias. 



20. An individual from which the exterior shell has been exfoliated, showing smooth annula- 

 tions whose greatest diameter is near the upper edge. 



21. A portion of the same en'arged, showing the appearance of the annulations magnified. 



Fig. 22 & 2.S. Tentaculites irregularis. 137 



[Echinus gyracanthus .- Eaton, Geological Text-book, 1832. This name was overlooked in the 

 synonymy, and the specific designation of Eaton has precedence over my own.] 



22. A small portion of the surface of the stone, showing the abundant distribution of these 

 bodies. On this specimen, which has a length of five inches and an average breadth of a 

 little more than one inch, more than five hundred individuals may be counted; and the 

 layer beneath, for the thickness of a quarter of an inch, Is composed almost entirely of 

 these fossils, giving more than ten times as many as can be seen upon the surface. 



23. Enlargement of a single individual. 



