206 PALEONTOLOGY OF NEW YORK. 



each other about 6 mm., the bases nearly in contact ; there is an elongate, 

 non-celluliferous space at the center occupied by bullae, the cells immediately 

 adjacent being slightly larger than the others and much more oblique. 



This species in general appearance approaches very nearly to L. stellata, but 

 may be distinguished by the less prominent monticules, the absence of a pro- 

 nounced central depression, the operculated cell apertures, and the striato- 

 bulhate inter-apertural surface : in its conspicuous opercula it resembles Fistu- 

 lipora serrulata, but may easily be distinguished by its larger and more oblique 

 cell apertures, the larger apertures on the monticules and the absence of meso- 

 pores : nearly the same features distinguish it from F. umbilicata, F. variopora 

 and F. confertipora. 



Formation and localities. Hamilton group, York, Livingston county, and four 

 miles south of Le Roy, Genesee county, N. Y. 



LiCHENALIA PUSTULOSA, n. Sp. 



NOT FIGURKD. 



ZoARiuM consisting of free or incrusting explanate fronds, or of masses formed 

 by the superimposition of successive layers of growth ; thickness of fronds 

 observed from 2 to 5 mm. Under surface consisting of an epitheca with 

 strong, concentric wrinkles and undulations, and fine radiating markings, 

 caused by the recumbent portion of the cells. Cells tubular, rectangular or 

 slightly oblique to the surface, walls strong, smooth ; septa very thin, in some 

 of the cells moderately frequent, in others obsolete. Intercellular tissue 

 vesiculose, the vesicles near the base are. very irregularly disposed, more 

 regularly disposed above, having the appearance of septa, transversely 

 dividing the intercellular space, or of walled septate tubuli ; septa very 

 closely disposed, from sixty to ninety in the space of 5 mm. Cell apertures 

 circular, diameter about .25 mm., irregularly disposed, sometimes in contact, 

 and seldom distant more than one-half the diameter of an aperture. The 

 apertures are generally operculated, the opercula consisting of convex or sub- 

 conical plates extending entirely across the apertures ; sometimes they are 

 convex, with a comparatively prominent node at the center. Peristomes 



