234 PALEONTOLOGY OF NEW YORK. 



FAVICELLA, n. q. 

 Favicella inclusa. 



PLATE LVin, FIGS. 21, 22. 



T/iallostigina inclusa. Hall. Trans. Albany Institute, vol. x, p. 188. 1881. 



" i;ic2u«a2x>ra (in error), Hall. Report of State Geologist for 1883, p. 33. 1884. 



ZoARiUM consisting of thin lamellate expansions, free or incrusting other 

 objects ; thickness of observed specimens 1 mm. Cells tubular, cylindrical, 

 for nearly one-half their length parallel with, and resting upon the epi- 

 theca, then somewhat abruptly bending, continue almost rectangul.ar to the 

 former portion, opening directly outwai'd. Intercellular tissue vesiculose, 

 apparently forming tubuli about two-thirds the diameter of the cell tubes, 

 divided by thin, closely disposed septa. Cell apertures circular, diameter 

 about .25 mm., usually regularly distant a little more than the diameter of 

 an aperture. Peristomes slightly and equally elevated. Midway between 

 the cell apertures are comparatively strong, sharply angular ridges, which 

 unite and enclose the apertures in pentagonal or hexagonal vestibular areas. 

 The surface between the ridges and apertures is flat and occupied by minute, 

 angular mesopores, about ten in the space of 1 mm. 



Surface marked by low monticules, the centers of which are distant from 

 each other about 4 mm., and having cell apertures larger than those on other 

 portions of the frond, the vestibular areas having a diameter of nearly 

 1 mm. 



This is a characteristic form, and very distinct from any other at present 

 known in this geological horizon, with the exception of Fistulipora con- 

 strida, which sometimes resembles it in having circular cell apertures, with 

 thin, slightly elevated peristomes, surrounded by angular elevations ; but it 

 differs in having the whole interapertural space raised in angular elevations, 

 with minute, obscure mesopores occupying every portion. It resembles Seleno- 

 pora circincta and S. complexa, of the Upper Helderberg group, in having the 

 cell apertures enclosed in polygonal areas, but in those species both the 

 elevations and cell apertures are oblique, the apertures are strongly denticu- 



