CORALS AND BRYOZOA. 195 



LICHENALIA, Hall. 1852. 



(See pages 30 and 77.) 



LiCHENALIA STELLATA. 



PLATE LVIII, FIGS. 15, 18. 



LieheruUia stellata. Hall. Trans. Albany Institute, vol. x, p. 183. 1881. 

 " " " Report of State Geologist for 1883, p. 33. 1884. 



ZoARiUM consisting of lamellate expansions, free or incrusting, or of masses 

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

 in thickness from 1 to 5 mm. ; under surface consisting of a thin epitheca, 

 concentrically wrinkled, and with numerous fine, sharp, concentric striae, and 

 also, by rounded, somewhat obscure, radiating lines. Cells tubular, recum- 

 bent for a short distance, but for the greater portion of their length at right 

 angles or oblique to the surface; walls thin, smooth or slightly wrinkled; 

 septa moderately frequent. Intercellular tissue composed of vesicles ; near 

 the base these are large, irregular in size and arrangement, regularly super- 

 imposed above, forming septate inter-cellular tubuli, septa numerous, fifty or 

 sixty in the space of 5 mm. Cell apertures oval or slightly circular, 

 diameter .35 mm., sometimes opening directly outwafd, but usually a little 

 oblique to the surface, occasionally operculated, closely disposed, radiating 

 from the mticulae and frequently forming diagonally intersecting rows. 

 Peristomes thick, anterior portion slightly elevated, posterior strongly 

 elevated, oblique, .smooth. Interapertui-al space smooth. Surface marked 

 by prominent rounded monticules, the centres of which are distant about 

 6 mm., and have an elongate depression destitute of cell apertures ; the cell 

 apertures immediately adjacent to the depressions radiate therefrom, and 

 are larger than the others, having a diameter of .50 mm. The disposition 

 of the cell apertures in rows radiating from the central depressions give to 

 the monticules a stellate appearance. 



This species in its characteristic forms is easily recognized, but in some 

 fronds there are variations, in which the resemblance to other species is 

 greater : it most nearly resembles Fistulipora operculata, but may be distinguished 



