710 BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 



PLAGIOECIA LOBATA, new species. 



Plate 106, figs. 6 14. 



Description. The zoarium is formed of bilamellar, rounded and flabellate 

 lobes, branched in the same plane. The tubes are indistinct, arranged in regular 

 quincunx, ornamented with salient, widely spaced, and overlapping wrinkles. The 

 peristome is little salient, thin, elliptical, often acuminate distally. The ovicell is 

 large, globular, very convex, arranged transversely in the upper part of the lobe. 

 The zone of growth is thick, but not very wide. 



Measurements. Diameter of the peristome 0.10-0.12 mm. 



Variations. The lobes are very irregular in dimension; their base is more 

 or less narrowed. 



In tangential section we note that the tubes are perforated with the usual 

 tremopores. Their arrangement in fusiform, elongate, lozenge-shape areas proves 

 that their system of branching offers no peculiarity. 



The irregularity of the transverse sections is occasioned by the unequal diver- 

 gence of the tubes. 



Occurrence. Midwayan (Clayton limestone). Luverne, Crenshaw Counfy, 

 Alabama (very common) ; one mile west of Fort Gaines, Georgia (rare). 



C'otypes.Cai. Nos. 65422, 65423, U.S.N.M. 



PLAGIOECIA CLAVIOEDES, new species. 



Plate 106, figs. 15, 16. 



Description. The zoarium is flabslliform and incrusts shells. The tubes are 

 distinct, regularly clariform arranged in regular quincunx, the peristome is little 

 salient, elliptical, horizontal. The ovicell is large, globular, little distant from 

 the zoarial margin. The zone of growth is quite visible, but of little width and 

 thickness. 



Diameter of the peristome 0.12 mm. 



Measurements. 



Distance between the peristomes 0.30-0.40 mm. 



Separation of the peristomes 0.44-0.48 mm. 



Occurrence. Midwayan (Clayton limestone) : One mile west of Fort Gaines, 

 Georgia (very rare) ; Mabelvale, near Little Rock, Arkansas (rare). 

 Holotype.C&t,. No. 64424, U.S.N.M. 



PLAGIOECIA SUPERPOSITA, new species. 



Plate 106, figs. 17, 18. 



Description. The zoarium incrusts terebratuloid brachiopods; it is formed 

 of orbicular subcolonies adjacent and superposed. The tubes are little distinct, 

 cylindrical, short, arranged in quincunx at the center and in radial rows on the 

 margins, never bent upward; the peristome is thin, elliptical or orbicular, accord- 

 ing to its obliquity. The ovicell is long, convex, parallel to the zoarial margins. 

 The zone of growth is thick and is supported by the projecting basal lamella. 



