NORTH AMERICAN EARLY TERTIARY BRYOZOA. 713 



with numerous incomplete tubes. The tubes are cylindrical, very erect and wide 

 apart at the center, recumbent and very close together on the zoarial margins. 

 The peristome is orbicular at the center, elliptical on the margins. The ovicell is 

 large, transverse, smooth, quite convex. 



Diameter of the peristome 0.10 mm. 



Measuremen ts. 



Distance between the peristomes 0.30-0.40 mm. 



Separation of the peristomes 0.40 mm. 



Variations. This species sometimes emits subcolonies. The larva is affixed 

 somewhat at hazard and the zoaria are then deformed by the irregularities of the 

 substratum, which gives them the most varied aspects. Figure 5, plate 121, repre- 

 M'uts a multiple zoarium fixed on the radicell of an alga and which thus assumes a 

 very aberrant form. The tubes are frequently closed by a calcareous compact, 

 smooth lamella. 



This species is well characterized, first, by the thickness of the zone of growth; 

 second, by its tubes, which are more erect and more salient at the center than at the 

 circumference; and, third, by its peristomes, which are very close to each other in 

 the vicinity of the zoarial margins. 



Occurrence. Lower Jacksonian (Moodys marl) : Jackson, Mississippi (rare). 

 Middle Jacksonian: Wilmington, North Carolina (rare); near Lenuds Ferry, 

 South Carolina (rare) ; Eutaw Springs, South Carolina (rare) ; Rich Hill, 5i miles 

 southeast of Knoxville, Crawford County, Georgia (very rare). 



Vicksburgian (Marianna limestone) : Three miles southwest of Yosburg, Jas- 

 per County, Mississippi (rare). 



Cotypes.Czt. Nos. 65297, 65298, U.S.N.M. 



PLAGIOECIA GLOBULOSA, new species. 

 Plate 115, figs. 2-0. 



Description. The zoarium is a cylindrical, hollo-w Entalophora; it incrusts 

 very fine radicclls at their ramifications. The tubes are little visible, somewhat 

 convex, bordered by a very narrow thread ; the peristome is oblique, elliptical, reg- 

 ular, little salient, thin. The ovicell is very large, (jlobuhir, transverse, very salient, 

 smooth. 



Diameter of the peristome and of the tubes_ 0.14 mm. 



Distance between the orifices. _ _ 0.40-0.74 mm. 



Measurements. { <-, .. , , . , . - 



separation of the peristomes 0.60-0. <0 mm. 



Diameter of the branches 1.2 mm. 



Almost all the tubes of our specimens are closed by a calcareous lamella. As the 

 lamella of growth is very small, we must suppose that there is a long peristomie. 



Affinit'irs. This species has the exterior aspect of Mecynoecia quisenberryae, 

 but differs from it in its hollow zoarium with a threadlike cavity in its interior, in 

 the absence of overlapping wrinkles upon the tubes, and in its ovicell which is larger 

 and of a different form. 



