82 PALEONTOLOGY OF NEW YORK. 



LlCHENAUA 8ERIALIS, n. sp. 



PLATE Xtll, WIGS. 17, 18 ; AMD I'LATU XV, FIG. 6. 



In jMui LMkenalia torla. Hall. Thirty-second Kept. N. Y. State Mus Nat. Hist., p. 157. 1880. 

 Lieienalia tuHa {tortuona in en-oi). Report of State Geologist for 1882. Expl. pi. 13, tigs. 17, 18 ; pi. 15. 



fig. 6. 1883. 



ZoARiUM explanate, thin. Cells tubular, very oblique, alternating and imbri- 

 cating. Apertures circular, diameter .40 mm.; generally regularly disposed : 

 margins strong, the posterior portion elevated slightly more than the anterior. 

 Interapertural space marked by short interrupted striations. Maculae desti- 

 tute of cell apertures, distant from each other 6 mm. ; apertures adjacent to 

 them larger than on other portions of the frond. 



This species may be distinguished by the large, circular cell apertures, and 

 their regular arrangement. 



Formation and locality. Lower Helderberg group, near Clarksville, Albany 

 county, N. Y. 



LiCHENALIA DISTAN8. 



PLATE XV, FIGS. 8, 9. 



lAehetudia dAgtan», Hall. Thirty-second Kept. N. Y. State Mus. Nat. Hist., p. 157. 1879. 



Report of State Geologist for 1882. Expl. pi. 15, figs. 8, 9. 1883. 



ZoARiUM consisting of lamellate expansions, free or encrusting. Thickness 

 1 mm. Cells tubular ; apertures somew^hat variable, usually oval or nearly 

 circular, sometimes sub-quadrangular, and occasionally sub-triangular, length 

 from .35 to .44 mm., width generally a little less than the length ; irregu- 

 larly and very closely disposed: margins thin, not prominent, except at 

 the posterior end, where they are strongly and abruptly elevated. Mesopores 

 variable in size, from one to two ranges between adjacent apertures : margins 

 thin and slightly raised, rendering the mesopores obscure. Intercellular 

 space vesicular ; vesicles comparatively large. 



Over the greater portion of the specimen the margins of the apertures are 

 of equal height, but this is probably due to weathering ; on some portions of 

 the zoarium they are so sharply elevated that in an oblique view they have 

 the appearance of spines. 



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



