PLATE XVIII. 
Phylloporina asperato-striata (Hall). (Page 48.) 
Figs. 1, 2. A small fragment, natural size, and the surface enlarged. 
3. A more complete zoarium, natural size, showing the noncelluliferous side. 
4, 5. Two enlargements of the noncelluliferous side, exhibiting the asperate striati 
character which suggested the specific name. 
Rochester shale, Lockport, N. Y. 
Pseudohornera diffusa (Hall). (Page 50.) 
[See also PI. XXITI, figs. 1-3.] 
G, 7. Views of Hall's types, natural size. 
8. A portion of the noncelluliferous striated surface enlarged. 
9. An enlargement of the celluliferous face showing the arrangement and forn 
of the zooecia. 
Rochester shale, Lockport, N. Y. 
Nematopora minrita (Hall). (Page 58.) 
[See also PI. XXI, tigs. 8, 9.] 
10. Hall's type, natural size and enlarged. 
Waldron shale, Waldron, Ind. 
Pachydictya crassa (Hall). (Page 57.) 
[See also PI. XXI, figs. 14-16.] 
11, 12. Two enlargements of a fragment of this species, figured by Hall and Simp 
son as Stictopora sdtula. 
Rochester shale, Lockport, N. Y. 
Loculipora ambigna (Hall). (Page 53.) 
13. An almost complete zoarium, natural size. 
14, 15. Enlarged views of the opposite faces of the same specimen showing sligb 
differences in the character of each. 
16. An enlargement from the edge of specimen illustrated by fig. 13. 
Waldron shale, Waldron, Ind. 
TJiamniscus dichotomus (Hall). (Page 54.) 
[See also PI. XXVII, figs. 1-7.] 
17, 18. One of Hall's types, natural size, and enlargement of the same. 
The supposed original of these figures, as stated on page 54, proves to 1 ^ 
a small example of Pachydictya crassa. 
19. An enlarged view of the striated noncelluliferous face of Hall's second ty] 
of the species. 
Rochester shale, Lockport, N. Y. 
Pseudohornera niagarensis (Hall). (Page 49.) 
[See also PI. XIX, figs. 14-16.] 
20. View of a specimen of this species, natural size, figured by Hall as Fenestella. 
Rochester shale, Lockport, N. Y. 
All the figures on this plate are copied from Hall, figs. 1-9 and 17-20 being from Natui i 
History of New York, Paleontology II, 1852; figs. 11 and 12 from Vol. VI of the sai 
series; and figs. 10 and 13-16 from Eleventh Annual Report of the State Geologist 
Indiana, 1882. 
100 
