NORTH AMERICAN EARLY TERTIARY BRYOZOA. 665 



Measurements. 



Diameter of tube 0.26 mm. 



Maximum width of zoarium 0.60 mm. 



Length of tube__ - 0.60-0.90 mm. 



Diameter of peristome 0.16-0.24 mm. 



Length of peristomie 0.30-0.40 mm. 



Variation*. This species is very peculiar and easy to determine by its small 

 angle of divergence. The branches begin always with an isolated zooecium and each 

 recommences a series analogous to that which issues from the ancestrula itself. We 

 have thus successively: Zooecia 1. 2, 2, separated, bifurcation; 1, 2, 3, bifurcation; 

 1, 2, 3, 4 (in transverse rows), bifurcation. The variations of this species are con- 

 siderable, but invariably the angle of dichotomization remains very small. 



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

 mon) ; Eutaw Springs, South Carolina (rare) ; Wilmington, North Carolina (com- 

 mon ) . 



Cotypes. Cat. No. 65289, U.S.N.M. 



PROBOSCINA SUBECHINATA, new species. 



Plate 152, figs. 1-2. 



Description. The zoarium incrusts shells in claviform and triserial branches. 

 The tubes are distinct, cylindrical, arched, wrinkled transversally, in quincunx or in 

 transverse series. The peristome is thin, orbicular, oblique; the peristomie is rather 

 long and elevated to 45. 



Maximum width of zoarium __ . 1.6 mm. 



Mi iisurements. 



Length of tube.- _ 0.70-0.80 



mm. 



Diameter of peristome 0.18 mm. 



Affinities. The angle of divergence appears to be small. The zooecia arranged 

 in transverse series are frequent; the peristomies are always free and isolated. 



In zoarial aspect this species much resembles Proboscina ecMnata Reuss, 1865. 

 Unfortunately we are ignorant of the micrometric measurements of this species and 

 no specimen is known in the European museums. Canu in 1909 believed it ought to 

 be compared with Proboscina major Johnston, 1847, but this was only a suggestion. 

 The specimens of Proboscina. major Johnston, 1847, collected in the Mediterranean, 

 have a peristome somewhat wider than that of our American specimens of the 

 present species. 



Occurrence. Vicksburgian (Marianna limestone) : Near Claiborne, Monroe 

 County, Alabama (rare) ; Salt Mountain 5 miles south of Jackson, Alabama (rare). 



HoJotype.C&t. No. 65375, U.S.N.M. 



PROBOSCINA EXIGUA, new species. 

 Plate 118, figs. 7-9. 



Description-. The zoarium is multiserial and incrusts shells in branches en- 

 larged distally. The tubes are small, distinct, cylindrical, arranged in quincunx or 

 in transverse series. The peristome is thin, orbicular, salient. The branches are 



