744 BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 



peristome is elliptical, thin, horizontal. The ovicell is globular, placed around 

 some tubes, ornamented with wrinkles like the tubes. 



Diameter of the peristome 0.10 mm. 



Measurcm-en ts. 



Distance between the peristom.es 0.60 mm. 



Measurements. 



Separation of the peristom.es 0.40-0.50 mm. 



This superb species is well characterized. 



Occurrence. Vicksburgian (Marianna limestone) : Three miles southeast of 

 Vosburg, Jasper County, Mississippi (rare). 

 Holotype.Crt,. No. 65381, U.S.N.M. 



DIAPEROECIA ORBICULATA, new species. 

 Plate 153, figs. 9-15. 



Description. The zoarium is free, large, orbicular; the basal lamella is 

 striated concentrically. The tubes are distinct, cylindrical, rectilinear, arranged 

 in quincunx or more often in irregular radial rows; the peristome is thin, orbicular, 

 very oblique. The ovicell is large, transversely elliptical, more or less distant 

 from the zoarial margins. 



Diameter of the peristome 0.10 mm. 



Separation of the peristomes 0.36 mm. 



Distance between the peristomes in quincunx. 0.40-0.50 mm. 



Distance between the peristomes in rows 0.25-0.30 mm. 



This beautiful species is admirably characterized by its zoarium in the 

 Disooparsa form and by its zooecia arranged in radial rows. We have discovered 

 one specimen with an absolutely smooth ovicell. 



Occurrence. Vicksburgian (Marianna limestone) : One mile north of Monroe- 

 ville, Alabama (very common). 



Cotypes.Cnt. No. 65382, U.S.N.M. 



DIAPEROECIA CLAVA, new species'. 



Plate 154, figs. 1-9. 



Description. The zoarium is a multiserial, thick Proboscina form in which 

 the branches are short or elongated and are in the form of a club ; it incrusts shells, 

 bryozoa, Orbitoid foraminifera, and algae. When the zoarium is free, the basal 

 lamella is striated transversally. The tubes are indistinct, arranged in regular 

 quincunx, terminated by a very salient peristomie and elevated almost vertically. 

 The peristome is orbicular, thick, sharp. The ovicell is very large, very globular, 

 irregularly elliptical; the oeciostome is elliptical, transverse, directed proximally, 

 adjacent to a tube. The zone of growth is very thick. 



Diameter of the peristome 0.10-0.12 mm. 



Diameter of the apertura 0.06-0.08 mm. 



Measurements. 



Distance between the peristomes 0.30 mm. 



Separation of the peristomes 0.30-0.36 mm. 



Width of the branches . 1.5 mm. 



