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PAGE 



Figs. 1-4. MONOTRYPA TABTJLATA (Hall) 278 



1. Vertical fracture of a zoarium, natural size, showing corrugated 



zooecial walls. 



2. A portion of the same enlarged. 



3-4. Vertical and tangential sections, X 6. 



New Scotland formation, New York. 



Figs. 5-8. CALLOTKYPA STRIATA (Hall and Simpson) 271 



5. A fragment of limestone with small examples of this species, natural 



size. 



6, 7. A small fragment and a portion of the same enlarged. 



8. A further enlargement (X 18), showing the arrangement of the 

 zooacia and mesopores and the prominent spine, at the posterior 

 end of the zooacium. 

 New Scotland formation, New York. 



Figs. 9, 10. CALLOTRYPA MACROPORA (Hall) 271 



A branching fragment and a portion of the same enlarged. New Scot- 

 land formation, New York. 



Figs. 11, 12. ERIDOTRYPA CORTICOSA (Hall) 273 



A fragment, natural size, and a portion of the same enlarged showing 

 the thick walled zocecia. New Scotland formation, New York. 



Figs. 13-15. CHILOTRYPA CONSTRICTA (Hall) 269 



13. A small piece of limestone with fragments of this species. 

 14, 15. Two fragments enlarged, the first showing the regular arrange- 

 ment of the zooecia and the second showing several maculae. 

 New Scotland formation, New York. 



Figs. 16-18. ORTHOPORA OVATIPORA (Hall) 288 



16, 17. A fragment, natural size, and an enlargement of the same. 

 18. Surface of a fragment, X 18. 



New Scotland formation, New York. 



41 



