Measurements. 



660 BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 



Variations. We have figured some zoarial variations, one of which has a very 

 remarkable triangular palm tree shape. The zoarium is quite often free and the 

 basal lamella is smooth. The peristomie disappears sometimes; in which case 

 the zoarium offers the aspect of Cellulipora. 



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

 Georgia (common) ; Luverne, Crenshaw County, Alabama (very rare). 



Cotypcs.Cat. No. 65252, U.S.N.M. 



PROBOSCINA RUGOSA, new species. 



Plate 116, figs. 8-9. 



Description. The zoarium is biserial and incrusts shells and bryozoa. The 

 tubes are cylindrical, arranged alternately and covered with large transverse and 

 very salient wrinkles. The peristome is orbicular, thick, little salient. The 

 branches commence with a single zooecium .and terminate in two, three, or four 

 nonalternated ones. There are some secondary branches which commence with two 

 zooecia. 



Maximum width of zoarium 0.40 mm. 



Length of tubes. _. 0.80-0.90 mm. 



Diameter of peristome 0.20 mm. 



Occurrence. Middle Jacksonian: Eutaw Springs, South Carolina (rare). 

 Holotype.C&t. No. 65272, U.S.N.M. 



PROBOSCINA PROJECTA, new species. 

 Plates 116, figs. 6-7. 



Description. The zoarium is biserial and incrusts bryozoa, emitting branches 

 at the principal points of curvature. The tubes are indistinct, arranged alternately, 

 striated transversally. The peristome is thin, orbicular, oblique. The peristomie is 

 very salient and oblique. The branches commence always with an isolated tube. 



Maximum width of zoarium 0.60 mm. 



Length of tube 1.40 mm. 



Diameter of peristome 0.24-0.30 mm. 



Length of peristomie 0.30 mm. 



Affinities. This species differs from Prosboscina geminata in its larger peri- 

 stome (more than 0.20 mm.) and in its larger peristomie. 



Occurrence. Middle Jacksonian (Castle Hayne limestone) : Wilmington, North 

 Carolina (rare). 



Upper Jacksonian (Ooala limestone) : West bank Sepulga River, Escambia 

 County, Alabama (very rare). 



Holotype.Cat. No. G5271, U.S.N.M. 



Measurem ents. 



