PLATE XVII. 
Trematopora tuberculosa Hall. (Page 43.) 
[See also PI. XIII, flgs. 15, 16; PI. XXV, fig. 8.1 
Fig. 1. Surface of a well-preserved specimen, X 18. 
2, 3. Vertical and tangential sections, X 18. 
Rochester shale, Lockport, N. Y. 
Idiotrypa punctata (Hall). (Page 40.) 
[See also PI. XXIV, figs. 17-19.] 
4. A tangential section, X 18, passing close to the surface. 
.5. A vertical section, X 18. showing the characters of the mature region. 
6. A portion of fig. 4, X 50, showing the minute structure. 
7. Surface of a specimen, X 18. 
8. A tangential section, X 18, passing through a less mature region than that figure* 
in 4. 
Osgood beds, Osgood, Ind. 
9. A tangential section, X 18, introduced for comparison with fig. 8. 
10. A vertical section, X 18, passing through two layers of the zooecia. This speci 
men is less mature than Ulrieh's type of Idiotrypa parasitica, which furnishei 
the sections figured in 4, 5, and 6. 
Rochester shale, Lockport, N. Y. 
Callopora elegantula Hall. (Page 41.) 
[See also PI. XXVI, fig. 12.] 
11. A normal vertical section, X 18. 
12. A tangential section, X 18, in which three of the zooecia show opercula. 
13. A transverse section, X 18, illustrating the shape of the zooecia and mesopores i: 
the immature region. 
14, 15. Tangential and vertical sections, X 20, exhibiting slight variations from the above 
Rochester shale, Lockport, N. Y. 
Figs. 1-7 and 11-13 are copied from Ulrich, American Paleozoic Bryozoa, Journal Cic 
cinnati Society of Natural History. 
98 
