HYATTELLA, Hatt. 
Page 767. 
HyatTetia coneesta, Conrad. 
Figs. 10, 11,12. Front, profile and dorsal views of an average example, 
enlarged. 
Fig. 13. An internal cast of the pedicle-valve; showing the impression of the 
pedicle-cavity and muscular area. X 2. 
Fig. 14. A preparation showing the form of the brachidium. 
Fig. 15. A cardinal view of an internal cast. 
Fig. 16. The interior of a portion of the brachial valve; showing the narrow 
median division of the hinge-plate. x 5. 
Fig. 17. The same specimen viewed in profile from in front; showing the 
elevation of the lateral divisions. » 5. 
HINDELLA, Daymson. 
Page 769. 
Hinpetia Prinstana, Billings. 
Fig. 18. Dorsal view of a somewhat elongated shell. 
HrypEtta umponata, Billings. 
Figs. 19, 20. Dorsal and profile views of an average example. 
Middle Silurian. Junction Cliff, Anticosti. 
DAYTIA, Davinson. 
Page 768. 
Dayia NavicuLa, Sowerby. 
Figs. 21, 22, 23. Dorsal, profile and front views of the exterior, enlarged. 
Figs. 24, 25. Preparations showing the structure of the brachidium. (DNSOAavI.) 
Ludlow shales. Shropshire, England. 
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