28 PALEONTOLOGY OF NEW YORK. 



consisting of u strongly wrinkled epitheca. Cells tubular, arising from and 

 for tt short distance oblique to the epitheca, then turning abruptly upward ; 

 walls very thin. Septa infrequent or entirely wanting. Apertures circular, 

 diameter slightly more than .25 mm. ; irregularly, very closely disposed, fre- 

 quently in contact : margins thin, slightly elevated, ornamented with from 

 one to three very prominent spines. Mesopores very minute : margins thinner 

 than those of the apertures, but of the same height. Intercellular space 

 vesiculose; vesicles irregularly arranged, comparatively very large, frequently 

 from .25 to .33 mm. in diameter. 



This species may be distinguished by its closely arranged circular cell aper- 

 tm^es with spiniferous margins, in which characters it varies from any other 

 species of this formation. 



Formation and locality. In the shaly limestone of the Lower Helderberg 

 group, near Schoharie, N. Y. 



FiSTULIPORA PARASITICA. 



PLATE XIV, FIGS. 13, U ; ANU PLATE XXllI, FIG. 4. 



In part CdUopora parasitica. Hall. Thii-ty-second Rept. N. Y. State Mus. Nat. Hiat., p. 157. 1879. 

 " •• " *• Report of SUte Geologist for 1882. Expl. pi. 14, &ga. 18-18. 1883. 



ZoARiCM explanate, or ramose, with hollow branches, free or encrusting other 

 bodies. Thickness .75 mm. ; inner, or under surface consisting of a thin, con- 

 centrically wrinkled epitheca. Cells tubular; apertures oval or slightly 

 polygonal from mutual pressure, length from .25 to .33 mm., width from .17 

 to .25 mm. ; very irregularly disposed, sometimes in contact, at other times 

 distant .50 mm. or more: margins thin, slightly and equally elevated; fre- 

 quently with one or more minute spinules. Mesopores variable in size, some 

 having a diameter of only .10 mm., while others are equal to the cell aper- 

 tures: margins of the same thickness and height as those of the cell aper- 

 tures. Intercellular space vesiculose; vesicles sometimes regularly arranged, 

 appearing as septate tubuli; at other times irregular, especially near the base 

 of the cell tubes. 



