88 
IV. Chert Beds. 
III. Buff, vesicular Magnesian Limemstones. 
II. Bituminous Shales and Limestones. \ ^ceivulaiia Beds. 
( Bryozoa Beds. 
I. Pale-buff, massive Limestones. \ Stromatopora Beds. 
’ rieurotomana Beds. 
This grouping of the strata will hold good, I think, through¬ 
out the State, and perhaps in other regions. Judging from 
the fossils, the Acervularia Beds outcrop at Iowa City, and 
the Bryozoa Beds at New Buffalo, in Iowa. On the eastern 
side of the peninsula of Michigan, the rocks with Stromato¬ 
pora are seen to he succeeded downwards hy the recognized 
Corniferous limestone. Indeed, the two are here, as in lake 
Erie, but one mass, physically. 
DIAGNOSES OF NEW SPECIES. 
Fistijlipora labiosa. —Incrusting in thin layers; the deli¬ 
cate cell-mouths surrounded by distinctly elevated and tumid 
lips ; intercellular surface smooth ; intercellular tissue consist¬ 
ing of minute polyhedral vesicles—a radiating series often 
surrounding the minutely septate cells. Intercellular dis¬ 
tances .33 mm. (.013)*; diameter of cell-mouths .381 mm. 
(.015) ; distance of septa .102 mm. (.004). 
Fistelipora Saffordi. —Incrusting in thin layers; cell- 
mouths scarcely elevated, without thick lips ; intercellular sur¬ 
face generally exposing the minutely vesicular tissue ; vesic- 
ules often radially disposed around the ’cells. Intercellular 
distances .254 mm. (.01) ; diameter of cell-mouths from .355* 
mm. (.014) to .508 mm. (.020). 
Callopora punctillata. — Delicate incrustations; cells 
approximate, but cylindrical or compressed-cylindrical—occa¬ 
sionally crowded and sub-prismatic; intercellular structure 
minutely vesicular, or, in places, wanting. Intercellular dis¬ 
tances .127 mm. (.005) or less; diameter of cell-mouths .152 
mm. (.006). 
Favosites Alpenensis. —Related to Calamopora poly¬ 
morph Goldf. Always massive; mural pores arranged in 
one (sometimes two) irregularly or scarcely lineal series on 
each side—their margins indented instead of raised. Walls 
distinctly double, quite smooth ; septa extremely thin. Cells 
smaller and pores more numerous than in F Billingsi Romin- 
ger. Distance of pores 2.286 mm. (.09); of septa 1.270 mm. 
(.05). 
* Measurements in millimetres. Numbers in parenthesis are equiva¬ 
lents in inches. 
