662 
BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 
M easurements . — 
Maximum width of zoarium 
Length of tube 
Diameter of peristome 
0.60-0.S0 mm. 
0.60 mm. 
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)- 
Ilolotype. — Cat. 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. 
M easurements . — 
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). 
Ilolotype. — Cat. 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. 
M easurements . — 
Maximum width of zoarium 
Length of tube 
Diameter of peristome 
0.35 mm. 
0.30-0.40 mm. 
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 Kiver, east of Marianna, Jack- 
son County, Florida (very rare)- 
Holotype. — Cat. No. 65283, U.S.N.M. 
