PLATE 34 A. 



Fig. 1. 513. 3. ASTBOCEBIUM PYRIKORME. (P"?- 123.) 



la. A spheroidal form of this species. 



1 6. A turbinate form, the cells increasing rapidly iVoni a um row base. 



1 c. An irregular turbinate form of larger size. 



•1 d. A portion enlarged, showing tlie internal stiucture <if tlie cells. 



1 c. An enlarged portion from tlio inner «:ills of tlic colls, showing the graiuilatid or ])apillosc surfaci' from 



the bases of the spiniforni rays. 



Fig. 2, 3. 514. 4. Astbocerium constrictum. ( Piig- 123.) 



2 a. A fragment of a hemispheric mass, natural size. 



2 6. A portion of the same enlarged, showing the constricted growth at iiitrrvals. 



2 c. A transverse section of the same enlarged, showing tlie stellate cliaractur of the cuds of the columns. 



3 a. A small hemispheric form of this species. 



3 6. The base of the same, showing its mode of growth upon t)ie valve of an .\tryp.4. 



8 c. Profile view, showing the form and elevation. 



3 d. The base of a larger specimen, which commenced its growth upon a small shell. 



3 e. A portion of the surface enlarged, showing the form and apparent .stellate chanictor of tlie cells. 



