EXPLANATION OF PLATE XV. 



Mactra lateralis Say (p. 82). 



Figs. 1, 2. Opposite sides of a right valve. 



3. Enlargement of the hinge, showing the structure. 



Raxgia (Perissodon) mikok Conrad (p. 84). 



Figs. 4,5. Opposite views of a right valve, twice enlarged. 



6. Further enlargement of the hinge. 



Syndosmya xuculoides Conrad (p. 81). 



Figs. 7, 8. Opposite views of a right valve, imperfect at the posterior end, twice enlarged. 



9. Further enlargement of the hinge. 



Mactra (Schizodesma) delumbis Conrad (p. 82). 



Fig. 10. Copy of Mr. Conrad's figure of this species given in his Miocene Foss., PI. xv, fig. 1. 



CORBULA SUBCONTRACT A Whitf. (p. 88). 



Figs. 11, 12. Two views of a right valve, enlarged. 



13, 14. Upper and cardinal views of a specimen retaining the valves in position, enlarged. 



Corbula elevata Conrad (p. 86). 



Fig. 15. Eolarged view of a right valve. 



16. Interior of a right valve, natural size. 

 17, 18, 19. Three views of a specimen retaining the valves in position; twice enlarged. 



Corbtla idonea Conrad (p. 88). 



Fig. 20. Copy of Conrad's figure, Miocene Fossils, PL x, fig. 6; none of the New Jersey speci 



mens being sufficiently perfect to illustrate. 



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