CORALS AND BRYOZOA. 



211 



fertipora by the more prominent and distant monticules, the larger and more 

 distant sub-trilobate cell apertures, the stronger peristomes, the absence of 

 nodes on the peristomes, and the comparatively indistinct raesopores : from 

 F. serrulate by the larger cell apertures, their form and closer disposition, the 

 much greater variation in the size of the apertures and the absence of serrula- 

 tions on the peristomes. 



Formation and localities. Hamilton group, "West Williams, Ontario, Canada ; 

 shore of Canandaigua lake, and York, Livingston county, N. Y. 



FiSTULIPORA CONFERTIPORA. 



PLATE I.VIII, FIGS. 1-5. 



ThaUostigma confertipora. Hall. Trans. Albany Institute, vol. x, p. 184. 1881. 



" " " Report of State Geologist for 1883, p. 19. 1884. 



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

 by the superimposition of successive layers of growth ; fronds varying from 

 .50 to 5 mm. in thickness; the under surface consists of a thin, strongly 

 wrinkled epitheca, from which the cells arise, obliquely for a short distance, 

 but for nearly their entire length are rectangular to the surface ; cells tubular, 

 cylindrical, septate, transverse section circular ; septa thin, occurring at irreg- 

 ular intervals, infrequent ; cell walls thin, with numerous fine corrugations 

 which frequently resemble nodes, about six in the space of 1 mm. Intercel- 

 lular tissue composed of vesicles which are irregularly disposed near the base, 

 becoming more regular above, having the appearance of narrow septate tubuli, 

 from fifty to sixty septa in the space of 5 mm. Cell apertures circular, diameter 

 .30 mm., closely and irregularly disposed, very frequently in contact. Peri- 

 stomes moderately strong, distinctly and equally elevated, when well 

 preserved having several short spines, which sometimes form the most con- 

 spicuous feature of the surface. Mesopores minute, usually only a single 

 series between atljacent apertures ; margins elevated slightly less than the 

 peristomes. The surface is marked by low, rounded monticules, the centers 

 of which are distant from each other about 4 mm., disposed in diagonally 

 intersecting rows with their bases in contact. The cell apertures on the 



