228 . PALEONTOLOGY OF NEW YORK. 



space about 1.50 mm. in diameter destitute of cell apertures and occupied 

 by the minute mesopores, the apertures immediately adjacent being slightly 

 larger than the others. 



This species most nearly resembles Lichenalia cornuta, but may be distin- 

 guished by the larger cell apertures, the much less prominent denticula- 

 tions, the elevated interapertural surface and the presence of mesopores : the 

 cell apertures and denticulations are of nearly the same appearance as 

 those of L. ramosa, but it may be distinguished by the elevated interapertu- 

 ral surface and the presence of mesopores : from Fistulipora unilinea by the much 

 more prominent denticulations, the elevated interapertural surface, the different 

 appearance of the mesopores, and the more frequent and prominent obtusely 

 conical monticules. 



Formation and localities. Hamilton group, four miles south of Le Roy, Gene- 

 see county, and York, Livingston county, N. Y. 



Fistulipora mdltaculeata. 



PLATE LIX, FIGS. 10, 11. 

 Thalloatigma multacideata, Hall. Report of State Geologfist for 1883, p. 23. 1884. 



ZoARiUM consisting of a thin foliaceous expansion, incrusting other objects, 

 especially Cyathophylloid corals ; the fronds observed are from .25 to .30 

 mm. in thickness, and have sometimes a digitate form. Cell apertures 

 oval, length about .25 mm., width a little more than one-half the length ; 

 irregularly disposed, sometimes in contact, at other times separated by more 

 than the width of an aperture. Peristomes strong, distinctly and equally 

 elevated, and when well preserved having several small nodes or spinules. 

 Mesopores small, from one to three series between adjacent apertures, but 

 generally not more than two ; margins elevated slightly less than the peri- 

 stomes, and having similar nodes at their angles. Surface not marked by 

 monticules or maculae. 



This species most nearly resembles F. intercellata of the Upper Helderberg 

 group, but it may be distinguished by the somewhat larger and more distant 



