656 BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 



STOMATOPORA POLYGONA, new species. 



Plate 115, figs. 9-11. 



Description. The zoarium incrusts shells and orbitoid foraminifera on which 

 it forms more or less regular polygons; the angle of dichotomization is very obtuse 

 and close to 120. The tubes are thin, cylindrical. The pcristome is thick, round, 

 little salient. 



Diameter of tube 0.10-0.12 mm. 



Measurements. Length of tube 0.56-0.60 mm. 



Diameter of peristome 0.10 mm. 



This very interesting species is easily recognized by its small polygonal zoaria. 



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

 Middle Jacksonian: Wilmington, North Carolina (very common), Eutaw Springs 

 (rare), and near Lenucls Ferry, South Carolina (very rare). 



Upper Jacksonian (Ocala limestone) : West bank Scpulga River, Escambia 

 County, Alabama (rare) ; Old Factory about H miles above Bainbridge, Georgia 

 (rare) ; and below Plant System Railroad Wharf, Bainbridge, Georgia (very 

 rare). 



Vicksburgian (Marianna limestone) : One mile north of Monroe ville, Ala- 

 bama (very 1 rare) ; and Salt Mountain, 5 miles south of Jackson, Alabama (rare). 



botypes.Czt No. 65277, U.S.N.M. 



STOMATOPORA MINUTA, new species. 



Plate 162, fig. 21. 



Description. The zoarium incrusts orbitoid foraminifera. The tubes are 

 cylindrical, small, smooth. The peristome is thin, salient, elliptical. 



Diameter of tube 0.10 mm. 



Length of tube. 0.20 mm. 



Diameter of peristome 0.10 mm. 



Occurrence. Vicksburgian (Marianna limestone) : Murder Creek east of Cas- 

 tlebury, Conecuh County, Alabama (very rare). 

 Holotypc.Cat. No. 65475, U.S.N.M. 



STOMATOPORA EXCAVANS, new species. 



Plnte 115, fig. 1. 



Description. The zoarium incrusts shells, in which it appears to excavate 

 furrows. The tubes are club-shaped, very narrow behind and raised almost ver- 

 tically at their extremity. The peristome is thin, oblique, orbicular, or elliptical. 



Length of tubes__ . 0.48-0.50 mm. 



Measurements. 



Measurements. \ ,-,. 



Diameter of peristome__ 0.10-0.12 mm. 



Affinities. This species differs from Stomatopora cornu, in which the tubes 

 are also club-shaped, by its smaller micrometric dimensions. 



