XVI LIST OF ILLUSTEATIONS. 



Page. 

 Fig. 141. Lioclema vetustum. a, a zoarium, natural size, incrusting an 

 Echinospherites; h, tangential section, X 20; c, portion of the 

 same, X 35; d, vertical section, X 20 247 



142. Lioclema spineum. a, tangential section, X 9; 6, the detailed struc- 



ture of an acanthopore, X 40; c, portion of a tangential section, 



X 20; d, vertical section, X 20 248 



143. Lioclemella clava. a, the type-specimen, natural size; 6, tangential 



section, X 20; c, vertical section, X 8; c?, portion of the same, X 20. 250 



144. Orbipora distincta. a and h, basal and celluliferous sides of a young 



zoarium, natural size, described by Eichwald as Chaetetes hemi- 

 sphericus; c, side view of the same specimen; d, celluliferous 

 surface enlarged. (After Eichwald.) 253 



145. Orbipora distiucta. a and 6, top and side views, natural size, of one 



of Eichwald's type-specimens of Orbipora distincta; c, celluliferous 

 face enlarged; d, worn portion of zoarial base enlarged; e, vertical 

 section; /, g, and h, views of a larger example; i, side view of 

 zooecial tubes. (After Eichwald.) 253 



146. Orbipora distincta. a, tangential section, X 20; 6, vertical section, 



X 8; c, small portion of the same section, X 20 254 



147. Orbipora distincta. a, tangential section, X 20; 6, a portion of a zooe- 



cial wall, X 35 254 



148. Orbipora solida. a, side view, natural size, of the type-specimen; 



6, tangential section, X 20; c, vertical section, X 8; (?, another 

 vertical sedtion, X 20 256 



149. Orbipora acanthophora. a, type-specimen, natural size; 6, tangen- 



tial section, X 20; c, several zooecia of the same section, X 20; 



rf, vertical section, X 20 257 



150. Orbipora indenta. a, the type zoarium, natural size; 6, tangential 



section, X 20; c, portion of the same section, X 35; d, vertical 

 section, X 20 258 



151. Esthoniopora communis, a and h, two vertical sections, X 20 260 



152. Esthoniopora communis, a, side view of an average specimen, natu- 



ral size; h, basal view showing epitheca and cicatrix of attachment; 

 c, tangential section, X 20, of average zooecia; d, several zooecia of 

 the same section, X 35; e, vertical section, X 8;/, portion of the 

 same section, X 20 261 



153. Esthoniopora communis, a, tangential section, X 20; 6, vertical sec- 



tion, X 20; c, a zooecial tube of the same section, X 20; d, vertical 

 section, X 20 262 



154. Esthoniopora communis, a, tangential section, X 20; h, vertical sec- 



tion, X 6, through a single zoarial layer; c, a portion of the same, 



X 20 262 



155. Esthoniopora communis. An unusual form of zoarium, natiu-al size. . 263 



156. Esthoniopora cujvata. a and h, side and basal views of a normal 



example, natural size; c, tangential section, X 20; d, vertical section 



X 8, through portions of two layers ; e, another vertical section, X 20 . 264 



157. Petalotrypa folium, a, surface of the type-specimen, X 9; &, tan- 



gential section, X 20; c, a few zooecia of the same, X 40; d, vertical 

 section, X 20 266 



158. Trematopora primigenia. a to c, three fragments, natural size; d, 



base of a zoarium, life size; e, surface of a typical example, X 9; 

 /, surface of another specimen, X 18; g', the usual appearance in 

 tangential section, X 18; /«, several zooecia of the same section, X 50; 

 i, vertical section, X 18. (After Ukich.) 269 



