EXPLANATION OF PLATE VII. 

 Arca (Latiarca) idonea Conrad (p. 47). 



Fig. 1. Copy of Conrad's figure of the species, Miocene Fobs., PI. xxix, fig. 3, no fragment from 



New Jersey being perfect enough to figure. 



Arca (Barbatia) Marylandica Conrad (p. 48). 



Figs. 2, 3. Exterior and interior of the largest fragment observed. 



4. Copy of Conrad's original figure, Miocene Foss., PI. xxix, fig. 1. 



Axinea lentiformis Conrad (p. 49). 



Figs. 5, 6. Two views of the largest specimen observed. 



Nucula proxima Say (p. 50). 



Figs. 7, 8, 9. Three views of specimens of the species, enlarged two diameters. 

 10. Further enlargement of the surface. 



Yoldia limatula Say (p. 51). 



Figs. 11, 12. Views of two valves of the species, the first enlarged two diameters. 



A st arte distans Conrad (p. 53). 



Fig. 13. Exterior of a small specimen showing crowded undulations. 

 14, 15. Opposite views of a right valve. 

 16, 17. Similar views of a left valve. 



*158 



