171 



in the center; triang'nUir spinnles at anolew of cell rims, 

 sometimes on sides. 



Fonnd in the Demissa and Stictopora beds, at Section .'). 



Paleschaka RETK'Tr>ATA. Hall. (Fio-. 66.) (3d Ann. 

 Rep't N. Y. State Geol., p. 6. ) 



Distinguishing Clmrncters. — Thin 

 incrustation ; pentagonal, hexago- 

 nal, or quadrangular cells, .35 mm. 

 in diameter, in contact, and vari- 

 ously disposed ; general appearance 



^C p„ „pj. i* I J. -J- Fig. 6fi. Paleacltura reticulattt. 



Ol SUrtace Otten reticulate; mmute a froud encrusting a coral; natural 



• , .••• \ 11 j_-i t ~ size, and a portion of the surface 



mtei-Stltml cells; monticules 4 or O enlarged, showing the monticules. 



,. , . From the Demissa bed. (Original.) 



mm. distant; central space \\\W\ 



cells .45 or .50 mm. in diameter; marginal spinnles in well- 

 preserved specimens. 



Found in the Demissa bed, at Section 5. 



Paleschara AMPLEL'TENS. Hall. (Xothgurcd.) (3d Ann. 

 Rep't X. Y. State Geol., p. 7. ) 



Distinguisliing i'lmrncters. — Extremely thin incrustation, 

 commonly on crinoid stems; quadrangular to hexagonal 

 cells, 2 mm. in diameter; minute marginal nodes or spin- 

 nles; no monticules or macul;e, but cells all of same size. 



Found in the Demissa bed, at Section 5 (rare). 



Gexus LTCHENALIA. Hall. 



[Ety. : From resemblance to a lichen.] 

 (1852: Pal. X. Y., Vol. 11. , p. 171.) 



Zoarium massive, or growing in circular or flabellate 

 expansions, celluliferous on one side, the other covered with 

 an epitheca. Cells arising from the epitheca, with transverse 

 tabuhp, and circular or trilobate, sometimes operculate, 

 apertures, which ai*e often denticulate, and have the pos- 

 terior portion of the peristome arched and elevated. Space 

 between apertures smooth. Intercellular spaces vesicular. 



LiCHENALiA stellata. H.dl. (Fig. ()6A.) (Pal. \. Y., 

 Vol. VI., p. 195, PI. LVIII.) 



