CORALS AND BRYOZOA. 
205 
Lichenalia bullata, n. sp. 
PLATE LVII, FIGS. 12, 13. 
Zoarium consisting of free or incrusting explanate fronds. Cell apertures 
circular or oval, diameter .50 mm. Peristomes moderately thick, the pos¬ 
terior portion the more strongly elevated, a little oblique. Inter-apertural 
space occupied by vesicles nearly equal in diameter to the cell apertures. 
Sometimes on portions of a frond the vesicles are much enlarged and the 
cell apertures correspondingly small. 
Formation and localitij. Hamilton group, four miles south of Le Roy, Genesee 
county, N. Y. 
Lichenalia operculata, n. sp. 
NOT FIGURED. 
Zoarium consisting of free or incrusting lamellate expansions, or of masses, 
formed by the superimposition of successive layers of growth; thickness of 
fronds from .50 to 5 mm. Cells tubular, cylindrical, rectangular or slightly 
oblique to the surface; septa thin, moderately frequent. The intercellular 
space is vesiculose; near the base the vesicles are large and very irregularly 
disposed; they are smaller and regularly superimposed above, frequently 
having the appearance of walled septate tubuli, with from twenty-five to 
forty septa in the space of 5 mm. Cell apertures circular, often pustuliform, 
oblique to the surface, diameter .40 mm., radiating from the centers of the 
monticules, generally forming closely disposed, diagonally intersecting rows, 
frequently in contact, usually operculated; the opercula are conspicuous, 
consisting of thin, slightly convex plates, extending entirely across the cell 
apertures. Peristomes thick, sometimes equally elevated, but usually the 
posterior portion is the more prominent, oblique, longitudinally striated. 
Inter-apertural space occupied by bullae, which are marked by short, broad, 
interrupted striations; when the frond becomes slightly worn these bullae 
are broken away, leaving the appearance of shallow angular pits. Surface 
marked by broad, rounded monticules, the centers of which are distant from 
