NORTH AMERICAN EARLY TERTIARY BRYOZOA. 



367 



Affinities. The distal part of the zooecia is often wider than the proximal 

 part, which gives them the aspect of a broad head. 



This species differs from the recent Eniballotlieca quadrata MacGillivray, 1880, 

 in its smaller micrometric dimensions and the entire absence of a mucro concealing 

 the rimule. 



This is a magnificent species, of which only two specimens have been found. 



Occurrence. Middle Jacksonian (Castle Hayne limestone) : Wilmington, North 

 Carolina (rare). 



Holotype.Czi, No. 640G9, U.S.N.M. 



FIG. 110. Genus Tetraplaria Tenison-Woods, 1S7S. 



A. Tetraplaria australis Teuison-Woods, 1878. Zooecia. (After MacGillivray 1895.) 



B, C. Tetraplaria (Pollaploccium) yilbcrtcnsis Maplestone, 1909. Zoarium, X 12, and 

 aperture. (After Maplestone, 1909.) 



D-F. Tetraplaria (Arliorclla) dichotoma Osburn, 1914. D. Zooecia. E. Portion of colony, 

 showing mode of growth. F. Operculum. (D-F after Osburn, 1914.) 



Genus TETRAPLARIA Tenison-Woods, 1878. 



1878. Tetraplaria TENISON-WOODS, On some Australian Tertiary fossil corals and Polyzoa, 

 Journal arid Proceedings of the Royal Society New South Wales, vol. 12. p. 61. 

 Synonyms PoUnploeciaiii MAPLEKTONE, 1D09, and Arborclta OSBITRN, 1914. 



The zoarium is articulated. The zooecia are arranged in pairs, back to back, 

 facing four ways; the opposite pairs of two sides alternating at right angles with 

 the other two. 



Genotype. Tetraplaria australis Tenison-Woods. 1878. 



The known species of this genus are : 



Tetraplaria australis Tenison-Woods, 1878. Fossil. 



Tetraplaria (Pollaploccium) gilbertensis Maplestone, 1909. Recent. 



Tetraplaria (Arborella) dichotoma Osburn, 1914. Recent. Florida. 



Tetraplaria (Cellaria) schreibersi Reuss, 1869. Fossil. 



