282 
PALEONTOLOGY OF NEW YORK. 
Surface marked by comparatively strong annulations, concentric and fine 
longitudinal striae. 
This form, in being parasitic, procumbent and increasing by gemmation, 
resembles the genus Aulopora, but the budding is always lateral, the young 
cells, for some distance, are in contact and frequently coalescing, with the 
parent cell; the gemmation is more irregular and occurs nearer the base. 
Formation and locality. Hamilton group, Cazenovia, Madison county, N. Y. 
BOTRYLLOPORA, Nicholson. 1874. 
Botryllopora socialis. 
PLATK I.XIV, FIGS. 3, 4. 
Botryllopora socialist, Nicholson. Geological Magazine. April, 1874. 
“ “ '* Pal. Province of Ontario, Canada. 1874. 
“ “ Hall. Report of State Geologist for 1SS3, p. 61. 18S4. 
Zoarium consisting of small discoid bodies, occurring singly or in groups, con¬ 
nected by vesicular tissue, adherent to foreign bodies by their under surface 
which consists of a concentrically wrinkled epitheca: nearly all the specimens 
observed are parasitic on Cyathophylloid or Favositoid corals, sometimes occur¬ 
ring in groups of from seventy-five to a hundred zoaria; each one having a diam¬ 
eter of from 3.50 to 4 mm., convex, with a concave central area, which is some¬ 
what variable in size, but usually from 1 to 1.50 mm. in diameter. Cells 
tubular, rectangular to the surface, disposed in double radiating rows, extend¬ 
ing above the surface and forming prominent ridges about .30 mm. in width; 
adjacent ridges generally separated by a space about equal in width to that 
of a ray, but sometimes more closely disposed. Alternate ridges extend 
from the margin to the depressed central area, the others from one-half to 
two-thirds that distance. Cell apertures minute, circular, diameter .10 or .12 
mm., in contact, often inosculating, having the appearance of being immersed. 
Each zoarium has from twenty to twenty-four rays, or from forty to forty- 
eight ranges of cells. Intercellular space vesiculose, vesicles comparatively 
large, and irregularly disposed. 
