198 
PALAEONTOLOGY OF NEW YORK. 
This species may- be distinguished by the sub-trilobate form of the apertures, 
their distance from each other, the nearly equally elevated peristomes and the 
smooth, flat, inter-apertural space. 
Formation and locality. Hamilton group. Western New York; particular 
locality not recorded. 
Lichenalia vesiculata, n sp. 
PLATE LVII, FIGS. 14-19; AND PLATE LIX, FIGS. 1, 14. 
Zoarium consisting of lamellate expansions free or incrusting other objects, 
generally Cyathophylloid corals ; no massive specimens have been observed; 
thickness of fronds from 1 to 3 mm.; under surface a thin epitheca with 
strong, concentric wrinkles, and obscure, rounded, radiating markings, caused 
by the recumbent portion of the cell tubes. Cells tubular, cylindrical, for 
nearly their entire length at right angles to the surface, septate ; septa very 
thin, moderately frequent; cell walls finely wrinkled or corrugated. Inter¬ 
cellular tissue vesiculose, vesicles comparatively very large and irregularly 
disposed near the base, more regularly superimposed above, but in the 
specimens observed, never having the appearance of walled septate tubuli; 
width of a vesicle generally about equal to that of a cell aperture, fifteen or 
twenty in the space of 5 mm., measured longitudinally. Cell apertures nearly 
circular, having a small fold or plication in the posterior portion of the walls, 
which frequently gives an obscurely trilobate or triangular form, diameter 
.50 mm., closely disposed, often in contact, frequently forming irregular, 
intersecting rows. Peristomes strong, equally elevated, not denticulated, 
when well preserved the summits are obscurely granulose, giving them 
a minutely, serrulate appearance. Inter-apertural space flat, when well 
preserved granulose, when slightly macerated smooth. Surface marked 
by elongate-depressed maculae, having a length of 5 mm., width about 1 
mm., and destitute of cell apertures. The cell apertures immediately adjacent, 
are not larger than the others and sometimes the general direction is not 
altered. On some fronds the cell apertures are distinctly trilobate (Plate 59, 
fig. 1), but these fronds, in all other respects, agree with the ordinary forms 
of the species. 
