Plate DG. 



Figs, l-l'i. Mi IriKlnUinn (UsKiniilc C;imi and Bassler, 1017 (p. 412). 

 1. The fi-ee, uarrow bilamellar zoarium, natural size. 

 2,3. Two views of normal zooecia, X 20. with a large spirainen .-lud witLi the oral 

 avicularia either absent or much reclnceil. 

 4. Normal zooecia, X 20, with the spiranieu and tlie two dissimilar avicularia. large 

 and small, well developed. 

 5,0. Normal and ovicelled zooecia. X 20. The latter have a lunate opening and are 

 without a spirauien. 



7. Zooecia, X 20, showing that the spiranien is often rei)laced b.v a rimnle spiramen. 



8. A group of ovicelled zooecia with adjacent normal zwecia, X 20. The frontal of 



both kinds of zooecia is a treniocyst. 



9. Another aspect of the species, X 20, in which the avicularia are s.vmiuelrical and 



tubular. 

 10, 11. Young zoaria. X 20. The avicularia are symmotrieal and tulmlar and the micro- 



nu'tric dimensions are smaller. 

 12. Interior of zooecia, X 20. Two zooecia liave tlie round spiramen while the rest 



have a rimule spiramen. Several ovicelled zooecia, with the aperture in tlie middle, 



may be noted. 

 13, 14. Tangential thin section, X 25 and X 100, passing through the tremocyst. 



15. Schematic vertical section, X 20, cutting an ovicelled zooecium. 



at), apertura: or, ovicell : pi, ijeristomie; pic, peristomice; tr, tremocyst: -. zooecium. 

 Middle JacUsonian (Castle Hayne limestone) : Wilmington. North Carolina. 

 Cat. No. G2596, T'.S.N.M. 

 Figs. 10-21. Mctiiiiloliiiiii coiivcniciix, new species (p. 445 i. 



16. Four examples of the bilamellar zoarium, natural size. 



17. Ordinary zooecia, X 20, with rimnle spir.-imen. One large ovicelled zooecium is 



developed. 

 IS. An example, X 20, showing ovicelled and ordinary zoaria. 



19. Ovicelled and ordinary zooecia, X 20. Some of the latter have only one large oral 



avicularium with pivot. 



20. Surface of zoarium, X 20, with ordinary zooecia having ,symmetrical avicularia and 



iio riinule spiramen. One ovicelled zooecium is present. 



21. Longitudinal section througli a zoarium. X 20, cutting lioth an ovicelled and an 



ordinary zooecium. 

 (III. .-uiertura: or. ovicell: pic. peristome: //■. tremocyst: c. zooecium. 

 .Middle .Tacksonian (Castle Hayne limestone): Wilmingtou. Nortli Carolina. 

 Cat. No. 04119. F.S.N.M. 

 55899— 20— Bull. 100 S ^' 



