NORTH AMERICAN EARLY TERTIARY BRYOZOA. 
405 
BATHOSELLA ASPERA Ulrich, 1901. 
Plate 1, figs. 27-31. 
1901. Mucronella aspera Ulrich, Maryland Geological Survey, Eocene, p. 221, pi. 60, figs. 
17, 18. 
1907. Mucronella aspera Weller, Geological Survey New Jersey, Paleontology, vol. 4, p. 354, 
pi. 26. figs. 14, 15. 
“Zoarium incrusting, consisting of one or more layers; surface under a low 
power of magnification, presenting a decidedly rough aspect. Zooecia varying 
from ovate-hexagonal to subrhomboidal, indistinct externally, arranged more or 
less irregularly, though the rows are more regular than they may appear at first 
sight ; about six in 2 mm. Apertures rounded or subquadrate, 0.13 mm. in diameter, 
rendered oblique by the elevation of the more or less strongly swollen posterior 
margin and the depression of the anterior part. The central portion of the raised 
lip forms a ‘mucro’ of greater or less thickness and prominence, the same hiding 
a minute central tooth beneath it and forming, with the rest of the thickened por- 
tion of the lip, a more or less obscure resemblance to the figure W. Behind the lip 
the surface slopes rapidly and in the most nearly perfect example is granulose. In 
the depressed space in front of the aperture there are, normally, three small raised 
avicularia (vibracula?) while a few larger avicularia, differing further from the 
others in being divided into two unequal parts by a crossbar, are scattered without 
order among the zooecia. Ooecia are not often seen. When present, they occupy 
the depressed space in front of the aperture, are cucullate, about as large as the 
zooecial aperture, and usually bear a furrow running from the summit to the 
concave edge.” 
Measurements. — Aperture 7ia= 0.12 mm. Zooeciajf S ~°'^ mm ' 
lfe=0.30-0.32 mm. 
There is very little to add to Ulrich’s excellent description quoted above. The 
wall of the ovicell is formed of two calcareous layers, but the upper layer is incom- 
plete and often forms a very narrow collar around the lower one. The avicularia 
symmetrically disposed on each side of the aperture are not rare. The zoarium 
is incrusting small shells. 
Occurrence. — Lowest Eocene (Bryozoan bed at base of Aquia formation) : 
Upper Marlboro, Maryland (rare). 
Geological distribution. — -Cretaceous (Vincentown limesand) : Vincentown, 
etc., New Jersey and Delaware. 
Plesiotype. — Cat. No. 63782, U.S.N.M. 
BATHOSELLA CINGERANS, new species. 
Plate 8, figs. 7-10. 
Description. — The zoarium is unilamellar, hollow, cylindrical; it creeps on 
the stems of the small algae which it often entirely surrounds. The zooecia are 
very little distinct, elongated; the frontal is convex and surrounded by a line of 
rather large areolae. The aperture is oblique, semilunar, and its proximal border 
