to. 1323. STRUCTURAL FEATURES OF HOMOTRYPA—BASSLER. 589 



Plate XXI. 

 HomotryiM dumosa, new species, p. 576. (See also Plate XX, fig. 1.) 



^'ig. 1. Fully matured region of a tangential Section X 20. 



2. Vertical section X 20. 



3. A complete zoarium, natural size. 

 Lorraine formation, Covington, Kentucky. 



Ilomotrypa cmc'mnatierms, new species, p. 576. 



•1^6. Three nearly complete zoaria, natural size, exhibiting variations in growth- 

 7, S. Tangential and vertical sections X 20. 

 9, 10. Tangential sections X 50 of zo(fcia in the peripheral region in different 

 stages of maturity. 

 Lorraine formation, Cincinnati, Ohio. 



Homotrypa JJabellaris var. spinifcra, new variety, p. 580. 



11. Portion of a frond, natural size. 

 12, 13. Nearly complete zoaria, natural size, of a narrow form of the variety. 

 14, 15. Vertical and tangential sections X 20. 



Lorraine formation, Covington, Kentucky. 



Plate XXII. 

 Homotrypa libana, new species, p. 578. 



^'ig. 1. Vertical section X 20. 



2. Tangential section X 20. 



3. Tangential section of several zooecia X 40, showing the intermural structure 



and the small acanthopores. 

 Lorraine formation, Lebanon, Ohio. 



Homotrypa nicklesi, new species, p. 586. 



4, 5. Vertical and tangential sections X 20. 



6. Tangential section of several zoircia X 40. 



7. Natural-size view of a fragment of a zoarium. 

 Richmond formation, Raywick, Kentucky. 



Homotrypa cylindrica, new species, p. 585. 



8, 9. Tangential and vertical sections X 20, illustrating the internal characters of 

 the species. 



10. Tangential section of several zoiocia X 40, showing the intermural structure 



and the large acanthopores witli the small central tube. 



11. Vertical section X 50, exhibiting structure of walls and cystiphragms. 

 12, 13. Natural-size views of two nearly comjilete zoaria. 



Riclimond formation, Richmond, Indiana. 



. Plate XXIII. 

 Homotrypa communis, new species, p. 581. 



?igs. 1, 2. Tangential and vertical sections X 20. 



3. Tangential section of a single zooecium X 50, showing the characters in the 



fully matured region. 



4. Natural size view of a small zoarium. 

 Richmond formation, Oregonia, Ohio. 



Proc. N. I\r. vol. xxvi— 02 40 



