NORTH AMERICAN EARLY TERTIARY BRYOZOA. 727 



Florida (common) ; Old Factory, about H miles above Bainbridge, Georgia (very 

 rare). 



Vicksburgian (Marianna limestone) : Salt Mountain, 5 miles south of Jackson, 

 Alabama (common) ; West bank Conecuh River, Escambia County, Alabama (very 

 rare) ; One milo north of Monroeville, Alabama (very common) ; Murder Creek, 

 east of Castlebury, Conecuh County, Alabama (very common). 



Geological distribution. Cretaceous-Recent. Cosmopolitan in Europe and 

 America. 



Habitat. Cosmopolitan in both hemispheres and in the warm and temperate 

 zones. This is a species of the depths; it appears first at 40 meters; attains its 

 maximum of abundance toward 100 meters, and may descend almost to 330 meters. 

 It affords, therefore, a very useful measure of depth. 



Plesiotypes.Cnt. Nos. 65437, 65438, U.S.N.M. 



MECYNOECIA LUVERNENSIS, new species. 



Plate 10, figs. 10-12. 



Description. The zoarium is an unbranched Filisparsa in which the noncellu- 

 liferous dorsal face is transversally wrinkled. The tubes are short, little visible, 

 elevated at their extremity and terminated by a very short peristomie elevated 

 almost vertically; the peristome is thick, orbicular. The ovicell is large, salient, 

 globular; the oeciostome is elliptical, salient, transverse, supported on another 

 tube. 



Diameter of the peristome 0.20-0.22 mm. 



Diameter of the apertura 0.16 mm. 



Diameter between the peristomes 0.25 mm. 



Occurrence. Midwayan (Clayton limestone) : Luverne, Crenshaw County. 

 Alabama (rare). 



Cotypes. Cat. No. 65257, U.S.N.M. 



MECYNOECIA CYLINDRICA, new species. 



Plate 127, figs. 1-7. 



Description. The zoarium is an Entalophora, regularly cylindrical, bifurcated. 

 The tubes are cylindrical, visible, separated by a very thin, salient thread; the 

 peristomes are salient, orbicular, regularly arranged in quincunx. The ovicell is 

 a large pyriform sack whose oeciostome is isolated. 



Diameter of the peristome 0.10-0.12 mm. 



Distance between the peristomes- _ _ 0.42-0.46 mm. 



J/ nxiin HK-ntS. o . .- - .1 n or 



separation of the penstomes__ (J.6(5 mm. 



Diameter of the branches 1.00 mm. 



Affinities. This species is very well characterized by its pyriform ovicell, its 

 cylindrical and regular branches, and by its zooecial margins. It is much smaller 



Measurements. 



