PLATE 24. 
1. 101. 2. CitAiTETES LYCOPERDON. (Pag- 64.) 
1 a. Section of a small hemispherical mass, showing the tubes nearly vertical to the base. 
1 b. A portion of the same magnified, 
1 c. The base of one of the hemispherical forms, where the polyps have just commenced their operations ; the 
tubes, though distinctly formed, have scarcely a perceptible elevation. The polyps here commenced their 
operations by attaching themselves to a valve of the Orthis testudinaria, and thence extended laterally 
on all sides. 
1 d. A small membranous envelope of this coral, from which, in some parts, the tubes have just commenced 
rising : this substance is thin, and concentrically wrinkled on both sides. 
1 e. A portion of an irregular massive specimen, showing a tendency to branching more distinctly than the 
specimens represented on Plate 23. 
1 f A few tubes of the same enlarged, showing the structure before exhibited in the hemispheric masses. 
1 g. A cylindrical branched specimen. 
1 h. A portion enlarged, showing the radiated tubes. 
1 i. Enlarged ends of the tubes on the surface of 1 g. 
ltii&l h. Smaller branched and cylindrical specimens. In these the direction of the tubes is more nearly in 
the direction of the axis of the coral, as shown in 1 o : they are, otherwise, similar to the previously 
noticed forms. The opening of the tubes upon the surface being likewise more oblique to the axis, they 
present a different form as represented in 1 n. 
2. 102. 3. Ch^etetes rugosus. (Pag. 67.) 
2 a. The specimen of the natural size. 
2 b. An enlarged portion, showing the form of the tubes and the rugose interior. 
3. 104. 1. Receptaculites neptunii? (Pag. 68.) 
3 a. The upper surface of the specimen, showing the quadrangular or rhomboidal openings upon the outside. 
3 b. A portion of the same enlarged, with a few of the openings, showing the aperture of the cylindrical tube 
within. The opening above is not entirely circular. 
3 c. Vertical section of the cylindrical tubes through the centre of the mass, as they appear on a weathered 
surface. As these converge towards the base, the ends only are seen as shown in the figure. 
3 d. Three of these tubes enlarged, showing a contraction or stricture near their upper termination, and the 
same below. 
