LIST OF ILLUSTRATIONS. XVII 



Page. 

 Fig. 159. Tfematopora kuckersiana. a, tangential section, X 20; b, vertical 



section, X 20; c, another vertical section 270 



160. Trematopora cystata. a and b, two fragments, natural size; c, tan- 



gential section, X 20; d, several zocecia, X 40; e, vertical section of a 

 branch 271 



161. Batostoma magnopora. a, small specimen of natural size; 6, tan- 



gential section, X 18; c, part of axial region in transverse section, 

 X 18; c?, vertical section of zoarium with a narrow mature zone, X 9. 

 (After Ulrich.) 273 



162. Batostoma magnopora. a, a small Russian example referred to the 



species, natural size; b, tangential section of same specimen, X 20; 



c and d, vertical section, X 10, and a portion, X 20 273 



163. Batostoma fertile, a and b, a large and a small specimen, natural size; 



c, surface of the larger specimen, X 9; (Z, tangential section of the 

 same example, X 18; e, vertical section, natural size, and a portion, 



X 18. (After TJkich.) 275 



164. Batostoma fertile circulare. a and 6, siirface of a typical example, 



X 9, with a portion, X 18; c and d, two tangential sections, X 18, 

 from different parts of the mature zone. (After Ulrich.) 276 



165. Batostoma mickwitzi. a, tangential section, X 20; b, vertical section, 



X8; c, several tubes of the mature zone, X 20, in vertical section; 



d, vertical section, X 20 277 



166. Batostoma winchelli. a and b, two fragments of natural size; c, sur- 



face of a, X 9 and X 18; d, tangential section, X 18; e, small por- 

 tion of a tangential section of a young specimen, X 18; /, several 

 zooecia of figure d, X 50; g, vertical section, X 18, of an ordinary 

 specimen. (After Ulrich.) 278 



167. Batostoma winchelli spinulosum. a, a Russian example, natural 



size; b, tangential section, X 20; c, several zooecia of another 

 tangential section of the same specimen, X 20, exhibiting the 

 normal development of acanthopores noted in American examples; 

 d, vertical section, X 20 279 



168. Batostoma winchelli spinulosum. a and 6, tangential section, *X 18, 



and a single zooecium, X 50, with numerous acanthopores. (After 

 Ulrich. ) 280 



169. Batostoma granulosum. a, the sectioned type-specimen, natural 



size; 6, tangential section of mature zone, X 20; c, vertical section, 



X 20 281 



170. Hemiphragma tenuimurale. a, the Russian example sectioned, 



natural size; b, view of tangential section; c, vertical section, X 20. 282 



171. Hemiphragma tenuimurale. Ulrich's views of the Minnesota types. 



a, surface of specimen, X 9; 6, vertical section, X 18; c, tangential 

 section, X 18 ,.- 283 



172. Hemiphragma irrasum. Views of the Minnesota types, after Ulrich. 



a and b, two fragments, natural size; c, surface of an average 

 example, X 9; d and e, tangential sections, X 18; /, vertical 

 section of branch, X 9 284 



173. Hemiphragma irrasum. a, view, natural size, of a zoarium; 6, 



tangential section of the same specimen, X 20; c, several zooecia. 



X 35; d, vertical section, X 20 285 



174. Hemiphragma panderi. a, vertical section, X 20; b, the usual view 



seen in tangential section, X 20; c, portion of same, X 40 286 



92602°— Bull. 77— U 2 



