The Nautilus. 



Vol. XXIII. MARCH, 1910. No. 10 



A NEW FOSSIL MITRA FEOM WEST FLOEIDA, AND A NEW EOCENE 



ASTARTE. 



BY T. H. ALDRICH. 



MiTRA (Chrysame) WALTONENSIS, n. sp. PI. XI, fig. 1. 



Shell rather solid, thick ; apex scarcely pointed. Whorls six, 

 three smooth, balance cancellated and shouldered, suture deep ; 

 varices near the aperture predominating over the spirals and ap- 

 pressed to the suture. Aperture with strong outer lip which is ser- 

 rated on its outer edge and showing seven or eight strong lirations 

 within ; inner lip curved and covered with a strong enamel which 

 spreads over part of the body whorl, two strong quadrangular folds 

 on the lower central part and a pointed tooth near tlie posterior part 

 of the aperture, base rounded, shell slightly umbilicMted. 



Height, 16 mm.; breadth, 9 mm.; length of aperture, 9 mm. 



Locality: Shoal River bed. West Florida. Oligocene of Dall. 



Remarks. — This is another Pacific Ocean form that adds to the 

 evidence of a channel between the two oceans during the Tertiary 

 period. 



AsTARTE NEWTONENSIS, n. Sp. PI. XI, figS. 2, 3. 



Shell small, rounded, nearly equilateral; beaks small, lunule 

 rather long, the concentric ribs dying down at the edge, but the 

 lines of growth run over to the hinge line and do the same on the 

 escutcheon also. Valves moderately convex, sculptured with nu- 

 merous small subequal ribs, inner margins crenulate, hinge as in 

 the figure. 



Height, 6 mm.; length, 7^ mm. 



