PLATE 32. 
Legend: dl. Dental lamellz. a. Anterior adductors. 
vs. Pedicle-cavity. a’. Posterior adductors. 
hp. Hinge-plate. r. Diductors. 
v. Vascular sinuses. 
WHITFIELDELLA, Iatt. 
Page 766. 
WHITFIELDELLA NiTIDA, Hall. 
Fig. 1. The cardinal portion of the pedicle valve; showing the teeth and the 
foramen almost inclosed by the substance of the valve. x 3. 
Figs. 2, 3. Dorsal and profile views of a large example. 
Fig. 4. The cardinal portion of the brachial valve; showing the medially 
divided hinge-plate. x 3. 
Niagara group. Waldron, Indiana. 
Fig. 5. An internal cast of conjoined valves; showing the position of the 
dental plates in the pedicle-valve, the impression of the divided 
hinge-plate, muscular scars and vascular sinuses on the brachial 
valve. X 2. 
Niagara dolomites. Milwaukee, Wisconsin. 
WHITFISLDELLA NAVIFORMIS, Hall. 
Fig. 6. The cardinal portion of a brachial valve; showing the structure of 
the hinge-plate, which was originally divided medially, the median 
cleft being partially filled by an erect lobe.  X 3. 
Clinton group. Western New York. 
WHITFIELDELLA INTERMEDIA, Hall. 
Fig. 7. Cardinal portion of the brachial valve; showing the median division 
of the hinge-plate. x 4. 
Clinton group. Hamilton, Ontario. 
WHITFISLDELLA CYLINDRICA, Hall. 
Fig. 8. Dorsal view of a large example. 
Fig. 
© 
. A preparation showing the mode of attachment of the spirals and 
the form of the jugum. 
Niagara group. Hillsboro, Ohio. 
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