PLATE 40. 
Legend: dp. Deltaria. j. Cardinal process. 
; t. Teeth. a. Adductor scars. 
S. Impression of primary r. Diductor scars. 
lamellee . 
CYCLOSPIRA, Hatt. 
Page 808. 
CycLosPirRA BISULCATA, Emmons. 
Figs. 1, 2, 3. Dorsal, profile and ventral views of a specimen bearing a mar- 
ginal plication in the sinus of the brachial valve. 2. 
Trenton limestone. Watertown, N. Y. 
PROTOZYGA, Hatt. 
Page 809. 
Protozyea Ex1qua, Hall. 
Figs. 4,5. Dorsal and ventral views of an average specimen. X 2. 
Trenton limestone. Watertown, N. Y. 
GLASSIA, Davinson. 
Page 811. 
GuassiA Romincext, Hall. 
Figs. 6, 7,8. Dorsal, ventral and profile views of the original specimen; 
showing the smooth bilobed exterior. X 2. 
Fig. 9. A preparation showing the introverted coils and the direction of the 
jugum. X23. 
Trenton limestone. rom the drift near Ann Arbor, Michigan 
HALLINA, N. H. Wincuetit anp ScuucHeErt. 
Page 810 
Hattina Sarrorpi, N. H. Winchell and Schuchert. 
Figs. 10, 11, 12. Dorsal, ventral and profile views of a typical example. x 5. 
Trenton limestone. Lebanon, Tennessee. 
ZYGOSPIRA, Hatt. 
Page 812. 
ZiGOSPIRA MODESTA, Say. 
Figs. 18, 14. Dorsal and profile views. 3. 
Fig.15. The interior of a brachial valve; showing the bilobed cardinal pro- 
cess. 2. 2 
Hudson River group. Near Cincinnati, Ohio. 
233 
