NORTH AMERICAN EARLY TERTIARY BRYOZOA. 729 



the peristomie depends upon how well the fossils are preserved. The quincunx 

 arrangement, of the peristomes is not very regular and we figure a specimen where 

 they are arranged in transversal rows. 



Affinities. This species differs from Mecynoecia compressa in its much shorter 

 ovicell, its zoarium less lamellar, and its shorter distance between the peristomes. 

 It differs from Ent+tlophora suhcompressa Eeuss, 1866, of which it is the American 

 representative, in the length of its peristomie. 



Occurrence. Middle Jacksonian : Eighteen miles west of Wrightsville, 

 Georgia (very rare) : Eutaw Springs, South Carolina (very rare) ; Georgia Kaolin 

 Company's mine, Twiggs County, Georgia (very rare) ; Eich Hill, five and one- 

 fourth miles south of Knoxville, Crawford County, Georgia (rare). 



Jacksonian (Zeuglodon zone) ; Shubuta, Mississippi (very rare) south side 

 of Suck Creek. Clarke County, Mississippi (very rare). 



Cotypcs.Cnt. Nos. 65466-65469 U.S.N.M. 



MECYNOECIA MAGNICELLA, new species. 



Plate 12S, figs. 1, 2. 



Description. The zoarium is an Entalophora with cylindrical branches. The 

 tubes are cylindrical, distinct, disposed in irregular quincunx, striated transver- 

 sally, vej^y large; bent upward at their extremity and terminated by an oblique, 

 little salient peristomie; the peristome is thick, orbicular, oblique. 



Diameter of the peristome : 0.24 mm. 



Diameter of the apertura 0.18 mm. 



Diameter of the zooecia 0.30-0.36 mm. 



Distance between the peristomes 1.40 mm. 



Separation of the peristomes . 1.40 mm. 



Maximum length of the peristomie 0.30 mm. 



Diameter of the zoarium 1.25 mm. 



This species is the largest of the American fossils described in the present 

 memoir. Its determination is therefore very easy. The ovicell is unknown. Only 

 the figured specimen has been collected. 



Occurrence. Upper Jacksonian (Ocala limestone) : Alaehun, Florida (very 

 rare). 



MECYNOECIA COMPRESSA, new species. 



Plate 155, figs. 1S-22. 



Description. The zoarium is formed of lamellar, cylindrical or slightly com- 

 pressed, fronds. The tubes are distinct, convex, striated transversally ; the peri- 

 stomes are little salient, thin, orbicular or elliptical, arranged in very irregular 

 quincunx. The ovicell is elliptical, very elongate, subsymmetrical ; the oeciostome 

 i^ transverse and placed on the peristomie of a tube. 



Diameter of the peristome O.l!> mm. 



Measurements- 



.]/< ilfilli'i mi. lit*. 



Distance between the peristomes 0.60 mm. 



Separation of the peristomes__ 0.52 mm. 



