Report of the State Geologist. 69 



cells, which have a diameter of .45 or .50 mm. When the surface 

 is well preserved the angles of the cell walls are ornamented with 

 small spinules. 



Sometimes there are remains of very fragile projections on the 

 margins of the aperture, which are probably the remains of a lip, 

 which extended partially over the aperture, as in the recent 

 Flustra. This feature if complete would give to the frond a very 

 different appearance from that which it now presents. 



This species may be distinguished from P. intercdla by its 

 somewhat larger cell apertures and more distant monticules ; from 

 P. variacella by the presence of interstitial cells, and the much 

 less variation in size between the ordinary cells and those on the 

 monticules ; from P. pertenuis by the more decidedly polygonal 

 cells, and the less crowded or confused appearance of the sur- 

 face ; from P. amplectens by the larger cell apertures ; from 

 P. incrustans of the Lower Helderberg group, by the more fre- 

 quent interstitial cells and the variation in size between the ordi- 

 nary cells and those on the monticules. 



Formation and locality. — Hamilton group, York, Livingston 

 county, N. Y. 



Palescliara Trariacella. 



Paleschara variacellay Hall. Trans. Albany Institute, vol. x, p. 179, 1881. 



Keport of State Geologist for 1883, p. 7, 1884. 

 '* '* " Palaeontology of New York, vol. vi, p. 237. 



Not figured, 1887. 



Zoarium consisting of extremely thin foliaceous expansions 

 incrusting other bodies, most frequently Cyathophylloid corals ; 

 greatest thickness observed .50 mm. Cells polygonal, from 

 quadrangular to hexagonal, diameter about .28 mm., sometimes a 

 little longer than wide ; in contact ; usually irregularly disposed 

 but sometimes in intersecting rows, the frond presenting a some- 

 what regular reticulated appearance. There are no interstitial 

 cells on the specimens observed. Surface marked by slightly 

 elevated monticules, the centers of which are distant about 4 mm. 

 with a space 1.50 mm. in diameter occupied by larger cells which 

 have a diameter of from .45 to .60 mm. The angles of the cell 

 walls are frequently ornamented by strong spinules. 



