PLATE LXXVIII. 



(rigiues 1-9, 17-23 by G. B. SiMI'Sos; 10-16 by U. 1' WmrFitLD.) 



Genus NEWBERRIA. Hall. 



Page 261. 



Newberria Clayi'olii, Hiill. 



Fig. 1. An internal ca.st of a portion of the pedicle-valve ; showing- the divergent impressions of the dental 



lamella;; the irregularly divided scar of the adductor muscles ; the narrow anterior adductor 



and strong vascular impressions. 

 Fig. 2. A portion of the interior of the bracdiial valve, drawn from a gutta-percha impression of a natui-al 



internal cast ; showing the division of the hinge-plate, and the st'iated adductor impressions. 

 Fig. 3. An internal cast of a small pedicle-vaive in which the impressions of the vascular sinuses are very 



strongly developed. 

 Fig. 4. An internal cast of a brachial valve preserving the usually elongate form of mature individuals, 



and showing the muscular and vascular impi-essions. 

 Fig. 5. The interior of a pedicle-valve, from a gutta-percha impression ; showing an open delthyrium, the 



divergent dental ) lates, the mus(udar and vascular impressions. 

 Fig. 6. An internal cast of the pedicle-v.alve ; showing the impression of the apical cup-shaped depression 



of that valve. By the i-emoval of the tilling of the dental sockets, the cardinal slope is made to 



appear unusually large and tiat. 

 Fig. 7. An internal cast of a large and symmetrical pedicle-valve. 

 Fig. 8. An internal cast of a large and somewhat deforaied brachial valve, which shows the usual size 



and division of the hinge-plate and the character of the adductor scars. 

 Fig. 9. An internal cast of a pL>dicle-va!ve in which the muscular scars and vascular .sinuses, both pri- 

 mary and secondary, are highly developed. 



Sandstones of the Hamilton group. PeiTy cotmtij, Pennsylvania. 



Newberria Johannis, Hall. 



Fig. 10. An internal cast of the umbonal portion of a pedicle-valve, with the muscular and vascular mark- 

 ings distinctly retained. 



Fig. 11. An inteiTial cast of the upper portion of a brachial valve ; showing the ca\ity left by the di\ided 

 hinge-plate and the adductor muscular scai-s. 



Figs. 12. 13. Doi-sal and ventral \iews of a large and chara<;teristic specimen ; .showing the elongate-oval 

 form, the decided median angulation of the valves and the rugose concentric growth of the 

 surface. 



Fig. 14. The exterior of a pe<licle-valve of a small individual. 



Pigs. 15, 16. Dorsal and profile views of a similar specimen ; showing the convexity of the vah'es. 

 Hamilton group. Waterloo, Iowa. 



Newberria l^vis (Meek .sp.), Wliiteaves. 



Figs. 17, 18. Dorsal and ventral views of an internal east 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 

 fine radiating stria; near the anterior margin of the specimen belong to the inner laminae 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, RampnHs of the Mackenzie Miver, British America. 



Newberria .Missouriensis, Swallow. 



Figs. 21, 22. Ventral and dorsal views of an individual from which the shell is partially exfohated. exposing 



the muscular and vascular impres.'^ions on the pedicle-valve. 

 Fig. 23. Profile of a large, gibbous individual. 



Hamilton group. Moniteau county, Missouri. 



