M> 111.17 





PLATE XLIII. 



Fig. 1. CYSTOIJHTYA HAMILTONENSIS Ulr. (See also PI. XLII.) J'.W 



Surface x9. 



Hamilton group, Buffalo, Iowa. 



Fig. 2. SCALABIPORA SEPARATA Ulr 5W 



An example of this spenies showing the widely soparated transverse 



earinw. Natural size. 



Hamilton group, Thunder Bay, Mich. 



Prof. A. H. Worthon's collection. 



Fig. 3. SCALABIPOKA APPBOXIMATA Ul 508 



An example of this species natural size. Like the preceding its surface 



is not well preserved. 



Hamilton group. Thunder Bay, Mich. 



Prof. A. H. Worthen's collection. 



Fig. 4. EUSPILOPOKA SEKKATA Ulr 526 



1. 4 a, 4 l> and 4 e. Four nearly complete examples from Buffalo, Iowa. 



E. 0. Ulrica's collection. 

 4 d. Another specimen from Thunder Bay, Mich. 



Prof. A. H. Worthen's collection. 



4 e. Surface xl8, showing arrangement of zooecia and granulose interspaces. 

 4 /. Tangential suction x 18. 



4 g. Portion of 4 /, x50, to show more clearly the minute structure of the 

 interspaces. 



4 h. Vertical section x25. 



Fig. 5. EUSPILOPOBA? BABBISI Ulr 527 



5. The largest specimen seen. Natural size. 



5 a. Surface of same x9. It is somewhat abraded. 



5 b. Vertical section, x!8, showing the tubular oblique zooecia and irregular 



median line. 



5 c. Tangential section. x!8. 

 5 rf. Transverse section, x 18, showing the peculiar form of the primitive 



portion of the zooecia and the irregularly flexuous mesial line. 



Hamilton group, Buffalo, Iowa. 



E. O. Ulrica's collection. 



Fig. G. INTRAPOBA COSCINIFOBMIS (Nicholson) 532 



6. Tangential section x!8, showing the thin zooecia walls and the numerous 



mesopores. 



tt a. A vertical section x!8, showing form of zocecia and the laminated 

 stru ture of the interspaces. 



Hamilton group, Arkona. Ontario. 



E. 0. Ulrich's collection. 



