Measurements. 



662 BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 



Maximum width of zoarium 0.60-0.80 mm. 



Measurements. Length of tube 0.60 mm. 



Diameter of peristome 0.20 mm. 



This very curious species with a flaccid aspect is easy to determine. 

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

 North Carolina (rare). 



Holotype.Ctf,. No. 65281, U.S.N.M. 



PROBOSCINA ALTERNATA, new species. 



Plate 120, figs. 11, 12. 



Description. The zoarium is biserial and incrusts shells in narrow branches. 

 The tubes are distinct, cylindrical, arranged alternately, striated transversely. 

 The peristome is thin, obliquely orbicular; the peristomie is very salient, oblique, 

 directed toward the exterior and alternately on each side of the median axis. The 

 branches commence with an isolated zooecium. 



Maximum width of zoarium 0.28 mm. 



Length of tube 0.40-0.60 mm. 



Diameter of peristome 0.12 mm. 



Diameter of peristomie 0.24 mm. 



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

 North Carolina (very rare). 



Holotype.C&t. No. 65282, U.S.N.M. 



PROBOSCINA DIVERGENS. new species. 



Plate 120, fig. 13. 



Description. The zoarium is biserial and incrusts shells, and bryozoa in recti- 

 linear branches. The tubes are cylindrical, alternated or opposite, finely striated 

 transversally, short. The peristome is thin, elliptical; the peristomie is rather 

 large and diverges from the median axis of the zoarium. 



Maximum width of zoarium 0.35 mm. 



Length of tube 0.30-0.40 mm. 



Diameter of peristome 0.10 mm. 



Affinities. This species differs from Proboscina alternata in its smaller tubes 

 (less than 0.40 mm.) and in its peristomes opposite and not alternated. 



Occurrence. Middle Jacksonian: Near Lenuds Ferry, South Carolina (very 

 rare) . 



Upper Jacksonian (Ocala limestone) : Chipola River, east of Marianna, Jack- 

 son County, Florida (very rare)- 



Holotype.CsA. No. 65283, U.S.N.M. 



Measurements. 



