BIRDSEYE LIMESTONE. 
I have annexed the following drawings illustrating the structure of this interesting fossil: 
35. 
The first (fig. 35) presents a view of its structure, as brought out by weathering : and ex¬ 
hibits longitudinal sections of a stem, and the small angular compartments, some of which 
are nearly transverse sections of a stem. 
The second (fig. 36) exhibits a magnified view of an oblique section, showing its cruciform 
structure. 
The remarkable structure brought out in this mode, principally by weathering, very clearly 
establishes the family of beings to which it belongs : It exhibits a perfect analogy to the class 
of Polypes, though none of the present species appear to assume this peculiar mode of 
growth. The following additional illustration shows the mode in which the stems appear to 
penetrate the beds of limestone with which it is associated: 
37. 
Fig. 37 shows the vertical arrangement of the individual stems and anastomosis, or free 
intercommunication which existed during the growth of the animal. 
