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Fig. 11. 
Figs. 12, 
Fig. 14. 
Figs. 15, 
PLATE LXXVIII. 
(Figures 1-9, J7-‘23 by G. 15. Simpson; i 5-16 by R. P, Whitfield.) 
Genus NEWBEKRIA, Hall. 
Page 261. 
Newberkia Clayi'olii, Hall. . 
An internal cast of a portion of the iiedicle-valve ; showing the divergent impressions of the dental 
lamellae ; the irregularly divided scar of the adductor muscles ; the narrow anterior adductor 
and strong vascular impressions. 
A portion of the interior of the brachial i-alve, drawn from a gutta-percha impression of a natural 
internal cast; showing the division of the hinge-plate, and the striated adductor impressions. 
An internal cast of a small pedicle-valve in which the impressions of the vascular sinuses are very 
strongly developed. 
An internal cast of a brachial valve preserving the usually elongate form , of mature individuals, 
and showing the muscular and vascular impressions. 
The interior of a pedicle-valve, from a gutta-percha impression ; showing an open delthyrium, the 
divergent dental) lates, the muscular and vascular impiessions. 
An internal cast of the pedicle-valve ; showing the imiiression of the apical cup-shaped depression 
of that valve. By the removal of the tilling of the dental sockets, the cardinal slope is made to 
appear unusually large and flat. 
An internal cast of a large and symmetrical pedicle-valve. 
An internal cast of a large and somewhat deformed brachial valve, which shows the usual size 
and division of the hinge-plate and the character of the adductor scars. 
An internal cast of a pedicle-valve in which the muscular scars and vascular sinuses, both pri¬ 
mary and secondary, are highly developed. 
Sandstones of the Hamilton group. Perry county, Pennsylvania. 
Newberria Johannis, Hall. 
An internal cast of the umbonal portion of a, pedicle-valve, with the musculai' and vascular mai'k- 
ings distinctly retained. 
An internal cast of the iqiper portion of a brachial valve ; showing the cavity left by the divided 
hinge-plate and the adductor musculai’ scai's. 
13. Dorsal and ventral views of a larg-e and characteristic specimen ; showing- the elongate-oval 
form, the decided median angulation of the valves ami the rugose concenti-ic growth of the 
surface. 
The exterior of a pedicle-valve of a small individual. 
16. Dorsal and jirofile views of a similar specimeti; showing the convexity of the valves. 
Hamilton group. Waterloo, loioa. 
Newberria la^vis (Meek sp.), Whiteuves. 
Figs. 17, 18. Dorsal and ventral views of an internal cast of a very large and symmetrical individual; 
showing the striated anterior adductor scars on the brachial valve, and the elongate muscular 
area, with the casts of the vascular sinuses in the umbonal region of the pedicle-valve. The 
tine radiating stria; near the anterior margin of the specimen belong to the inner latnince of the 
shell. 
Figs. 19, 20. Profile and dorsal views of an individual retaining the shell, and showing the normal convex¬ 
ity of the valves. 
Hamilton group, MaiwpaHs of the Mackenzie River, British America. 
Newberria Missouriexsis, Swallow. 
Figs. 21, 22. Ventral and dorsal views of an individual from which the shell is partially exfoliated, exposing 
the muscular and vascular impressions on the pedicle-valve. 
Fig. 23. Profile of a large, gibbous individual. 
Hamilton group. Moniteau county, Missouri. 
