50 
Figures 1, 
Figure 3. 
Figures 4, 
Figures 6, 
Figure 10. 
FIGURE 11. 
Figure 12. 
Figure 13. 
Plate YI. 
2. Platystrophia amoena McErran. (Page 17.) 
Brachial and pedicle valves of a normal, fully adult 
or slightly senile individual from the Trenton at Trenton 
Falls, N.Y. Specimen in the Museum of Comparative 
ZoOlogy. Natural size. 
Interior of the pedicle valve of a large adult, from the same 
locality and in the same collection as the last. Natural 
size. 
5. The same species. A not quite fully grown specimen from the 
same locality, and In the same collection. Natural size. 
7, 8 , 9. Platystrophia champlainensis McEwan. (Page 19.) 
Four views of a specimen from the lowest Treiiton at 
Montreal, Que. Twice natural size. No. 3243. 
Platystrophia minu.ta Raymond. (Page 20.) 
A fragment of rock with the hdlotype (brachial 
valve) and paratype (imperfect pedicle valve) of this 
species. From the lowest Trenton at Lorette, Que. 
No. 3242. 
Platystrophia amana McEwan. (Page 17.) 
A large and typical specimen from Ottawa; exact 
horizon unknown. No. 1628b. j 
Raflnesquina camerata s (Conrad). (Page 21.) 
A single very perfect pedicle valve from the -Colling- 
wood at Craigleith, Ont. Natural size. No. SEio’Ba. 
The same species. A slab with several exfoliated pedicle valves. 
From the same formation and locality as the above. 
Natural size. No. 3256. 
