PLATE 34. 



Fig. 1. 511. 1. ASTROCERIUM VENUSTUM. ( P^^g- 120.) 



1 a. A vertical section of a solid spheroidal mass, showing its columnar character, anil the lines indicatinfr 



stages of growth. 

 1 6. The base of a smaller solid specimen, showing the coral surrounding, and the columns diverging from 



a stem of the Syringopora multicavlis. 

 1 c. A vertical section, with the cells open, showing the intern.il character. 

 1 d. A portion enlarged, showing the arrangement of the spiniform rays between the septa. 

 1 c. A similar section wliore the rays are nearly obsolete. 



1 /. A section enlarged, showing the surface of the walls of the cell, where the rays arc broken off. 

 \ g. A single space between two septa, greatly enlarged. 

 1 A. A transverse section of the cells parallel to the surface. 

 1 t". The same enlarged. 



1 J. Surface of a specimen of this coral where the radiating lamellie are nearly obliterated, and showing a 



columnar structure. 



Fig. 2. 512. 2. AsTRocERiuM parasiticum. {^^8,- 122.) 



2 a. A small spheroidal form, attached to a coral which projects beyond the base. 

 2 fr. A small spheroidal s|>ccimcn. 



2 c. A spheroidal mass with the cells open on a part of the surface, sh^wing the unequal sine of the openings : 



the interspaces are also very wide. 

 2 d. A smaller ma.ss enclosing a piece of a crinoidal column, which projects on both sides of the coral. 

 2 e. Sections of a spherical mass, which enclosed a fragment of an iclithyodorulite. 



2 /. A portion of the surface from a large specimen, where the cells are filled, and the whole mass is columnar. 

 2 g. A small portion from the base of the last, showing the weathered surface of the columns. 

 2 A. The ends of the tubes enlarged, showing the stellate character. 

 2 i. Showing the papillose surface of the interior of the tube when the rays are broken away, leaving the 



bases projecting. 



