NORTH AMERICAN EARLY TERTIARY BRYOZOA. 113 



i;-nrr< nee. Middle Jacksonian: Wilmington, North Carolina (rare) ; Eutaw 

 Springs. South Carolina (rare) ; Kirh Hill, Crawford County, Georgia (common) : 

 18 miles west of Wrightsville, Jackson County, (Georgia (very rare). 



Upper Jacksonian (Ocala limestone) : 14 miles above Bainbridge, Georgia. 



(.'otypes.Cnt. No. C3878, U.S.N.M. 



HINCKSINA SMITHI, new species. 



Plate 21, figs. 15-17. 



Description. The zoarium incrusts pebbles. The zooecia are elliptical, dis- 

 tinct, and may or may not have a gymnocyst ; the mural rim is thin, salient, convex, 

 ornamented with 8 to 10 spines. The opesium is elliptical and very slightly 

 crenulated. The endozooecial ovicell is a quite visible convexity. 



. (Ao=0.30 mm. 



M, u-.il/-' mcnts. Opesia - 7 Zooecia 



* //I It \ J I) 1 / n-im 



|Zo=0.14-0.17 mm. 



Zs=0.40-0.45 mm. 

 lz 0.22-0.25 mm. 



s. The mural rim is sometimes enlarged a little at the base as in 

 r>calensis, but the dimensions are much smaller and the spines more nu- 

 merous. These same small dimensions and its very slightly crenulated opesium will 

 distinguish it from Hiiirkxiiu/ i-cplmix. 



Iliiirkxina smitM differs from the recent PI. maderensis Waters, 1898, in the 

 absence ot'die five peculiar distal spines and in its small ovicell. 



We dedicate this elegant species to Dr. Eugene A. Smith, State geologist of 

 Alabama, who has been ever ready to further our researches with material from 

 his State. 



i'ri -nee. Middle Jacksonian: Eutaw Springs, South Carolina (very rare). 

 No. 63877. U.S.N.M. 



HINCKSINA JACKSONICA Canu and Bassler, 1917. 



Plate 22, figs. 4-9. 



1917. Hincksina jacksonica CANU and BASSLER. Synopsis of American Early Tertiary 

 rheilustome Bryozoa, Bulletin 9G, United States National Museum, p. 15, pi. 1, fijj. 6. 



Description. The zoarium is free, bilamcllar. easily divisible into two layers. 

 The zooecia are elongated, distinct, elliptical, often with a small gymnocyst ; the 

 mural rim is convex, enlarged at the base, finely granulated. The opesium is 

 terminal, elliptical, regular, very finely denticulated. The ovicell is endozooecial 

 and little apparent; it appears as a small distal convexity. Avicnlarian zooecia 

 are very rare. 



[Ao=0.35-0.45 mm. . |Za=0.15-0.65 mm. 



Measurements. Opesia , Zooecia , 



|Z0=0.20-0.2o mm. |Za=0.3o-0.40 mm. 



The two lamellae forming the zoarium separate very easily, each preserving 

 it^ own base. 



Vii.t'iiitinn*. The zooecial length is quite variable; both long and short zooecia 

 may occur (fig. 6). The avicularian zooecia or interzooecial avicularia are rather 



.-,.-,80919 Bull. 106 -- 8 



