NORTH AMERICAN EARLY TERTIARY BRYOZOA. 405 



BATHOSELLA ASPERA Ulrich. 1901. 



Plate 1, figs. 27-31. 



1901. Hiicronella aspcra ULRICH, Maryland Geological Survey. Eocene, p. 221, pi. GO. figs. 



17, 18. 

 1907. Mucronella aspcra 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." 



rZ,s=0.40-0.50 mm. 



Measurements. Aperture foz=0.12mm. Zooecia-L 



lfe=0.30-0.32 mm. 



There is very little to add to Ulrica'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.Czt. No. 63782, U.S.N.M. 



BATHOSELLA CINGERANS, new species. 



Plate 3, 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 



