86 PALEONTOLOGY OF NEW YORK. 



8ub-imbricating; at other times presenting a reticulated appearance. Mar- 

 gins of the cell apertures frequently bearing short spinules on the angles. 



This species, in its cell apertures, is very similar to Alveolites, and its true 

 generic relations are still undetermined. 



Formation and locality. Lower Helderberg group, Schoharie, N. Y. 



Paleschara? tenuis, n. sp. 



ZoARiUM incrusting, very thin ; thickness sometimes not more than .10 ram. 

 Cells polygonal. Apertures occasionally circular, diameter .25 mm. ; irregu- 

 larly disposed, with frequent maculae of larger cells, having the apertures .33 

 mm. in diameter. 



This species is so thin that the arrangement of cells is sometimes de- 

 termined by the object incrusted ; some specimens growing upon Trematopora 

 {Orihopora) regularis have their cells disposed in longitudinal, parallel rows. It 

 may be distinguished from P. incrustans by its much smaller cells. 



Formation and locality. Lower Helderberg group, near Clarksville, N. Y. 



Paleschara ? (Lichenalia ?) bilateralis. 



PLATE XVI, F1G8. 22, 2S. 



Paleschara t UlateraHx, Hai.i,. Thirty-second Rept. N. Y. State Mus. Nat. Hist., p. 160. 1879. 



Report of State Geologist for 1882. Expl. pi. 16, figs. 22, 23. 1883. 



ZoARiUM consisting of an elongate, lamellate expansion, celluliferous on each 

 face; thickness about 1 mm. Cells tubular, arising from a mesotheca. 

 Apertures oval or polygonal, length .36 mm., width from one-half to three- 

 fourths the length ; sometimes irregularly disposed ; at other times in longi- 

 tudinal rows on the central portion of the frond, and on the lateral portions, 

 more irregularly disposed in oblique ascending series. The surface has 

 maculae of larger cell apertures. Intercellular space vesiculose. The sur- 

 face has not been observed in a perfect condition. Two fragments of this 

 Bpecies have been observed. 



