CORALS AND BRYOZOA. 
9 
Favosites conicus. 
PLATE III, FIGS. 4, (i-13. 
Favosites conical Hall. Twenty-sixth Rept. N. Y. State Mus. Nat. Hist., p. 112. 1874. 
“ “ “ Thirty-second Rept. N. Y. State Mus. Nat. Hist., p. 146. 1S79. 
“ conicus, “ Report of State Geologist for 1SS2. Expl. pi. 3, fig-s. 4, 6-13. 1883. 
Corallum forming conical masses; flattened at the base, which is covered by a 
strong epitheca, marked with concentric wrinkles and undulations and radi¬ 
ating undulations formed by the cell tubes. Cells arising from the center of 
the base and from an undefined central axis and quite abruptly curving to 
the surface, increasing by interstitial additions; polygonal, from four to eight¬ 
sided ; diameter at the surface varying from 1.5 to 3.5 mm.; walls compara¬ 
tively strong; interior with evidences of numerous spinules or small nodes. 
Septa of about the same strength as the walls, irregularly arranged, varying 
from eight to fifteen in the space of 10 mm. Mural pores comparatively 
large, circular, with distinctly elevated margins, disposed in one, two and 
sometimes three ranges. Where one or two ranges occur the pores are 
regularly arranged one above the other; where three ranges occur the dis¬ 
position is more irregular. 
The conical form of this species and the irregularity in the size of the cells 
distinguish it from every other known species of Favosites in the Silurian 
rocks of New York. 
Formation and locality. In the shaly limestone of- the Lower Helderberg 
group, near Clarksville, N. Y., and at Cumberland, Md. 
Favosites sphericus. 
PLATE VII, FIGS. 1-12; AND PLATE VIII, FIG. 8. 
Chcetetcs sphcBrica, Hall. Twenty-sixth Rept. N. Y. State Mus. Nat. Hist., p. 111. 1874. 
Favosites minimus, “ (In error) Thirty-second Rept. N Y. State Mus. Nat. Hist., p. 147. 1879. 
Not Favosites sphericus, Hall. (= Astylospongia) Thirty-second Rept N. Y. State Mus. Nat. Hist, p 
146. 1S79. 
Favosites sphericus, Hall. Report of State Geologist for 18S2. Expl. pi. 7, figs. 1-12. 1883. 
Corallum massive, variable in form. Cell tubes polygonal, generally hexagonal; 
length from 2 to 13 mm. or more; diameter from .25 to .35 mm. On the 
surface are frequent maculae .5 mm. in diameter, where the cells are larger 
