PLATE XV. 
Callopora wagnopora Foerstc. (Page 42.) 
[See also PI. XXVI, fig. 3.] 
1, 2. Tangential and vertical sections, X 20, of an authentic specimen. 
Clinton formation, Dayton, Ohio. 
3. Vertical section, X 20, showing the characteristic tabulation of the species. 
4. A small portion of a tangent ial section, X 20, cutl ing the mature region at a zone 
where the mesopores arc well developed. 
5. Several zooecia and mesopores, X 20, of a tangential section taken near the 
surface of the zoarium where the mesopores are few in number. 
6. Portion of a transverse section, X 20, showing the shape of the zooecia and meso- 
pores in the immature zone. 
7. A single zooecium from a deep tangential section, X 20, passing through a 
diaphragm and indicating that the opercula seen at the surface became 
diaphragms as growth proceeded. 
8. Surface of atypical example, X 8. 
Rochester shale, Grimsby, Ontario. 
Callopora dausa n. sp. (Page 42.) 
9. Tangential section, X 20, illustrating the polygonal rather thick-walled zocecia 
and few mesopores. 
10. Vertical section, X 20, showing characteristic tabulation of zooecia and meso- 
pores and disappearance of the latter as the surface is approached. 
11. A typical example, natural size. ,. 
12. Surface of same, X 8. Here only the crests of the zocecial walls are shown, 
the walls themselves being considerably thicker. 
Rochester shale, Lockport, N. Y. 
94 
