PLATE 29. 



Fig. 1. 126. 2. ScHizocKiNus? (Pag. 86.) 



Fig. 2 a, b. Bases of attachiuetil of CKiNoiDiiA. ' (Pag. 86.) 



Fig. 3 a, h, c. Columns of Ckinoiuea. ( Pag. 86.) 



Fig. 4. 127. 1. ECHINO-ENCIUNITES ANATIFORMIS. ( P^g. 89.) 



■1 a. The column, with a single detached plate near its upper termination. The long narrow joints of the co- 

 lumn, which gradually become shorter and broader until they form broad thin rings in the upper part, 

 are clearly shown. The plate belongs to the second range, and is hexagonal, with three prominent ridges 

 upon its surface. A curved depression on one side shows that it formed a part of the lateral aperture. 



4 b. Part of a similar column, with the plates of a crushed cup lying at its upper termination. There are, at 

 the summit of this specimen, one or two free nearly circular discs, and one apparently attached, as if 

 forming the base of the tentacula at one point. 



4 c. One of these plates enlarged. The surface is worn smooth, with the exception of the ridges on the plate. 



4 d. A larger and more perfect specimen ; the plates near the base showing the strong slriie upon their sur- 

 face, which are at right angles to the edges. 



4 c. The structure, as far as can be ascertained from our specimens. 



4 / Tlie surface ol' one of the plates, magnified, to show the striae. 



Fig. 5. 128. 2. AsTERiAS matutina. (Pag. 91.) 



5 a. The specimen, natural size. 



5 b. A portion enlarged, showing the form of the plates and the punctate surface. 



Fig. 6. 129. 1. Tentaculites? flexuosa. (Pag- 92.) 



a. A single specimen of this species, with a portion of the same magnified, showing tlie transverse septa, 

 ti i. A group of the same species, adhering by their smaller extremities to the dorsal valve of Ortliis tesludi- 



naria. At c, there is the base of several cells of the Chtetetes lycoperdon, adhering to the same sliell. 

 IJ d. A single tube magnified, showing more distinctly the striae upon the surface, and, also, in some degree, 



the irregularity of the annulations. 



