PLEIOCENE FOSSILS. 



PLATE XVI. 



ARCACIDiE. 



Fig. 1. AKCA SCALAKIS. Exterior of left valve, and binge and teeth of right valve. Page 43. 



" 2. End view, showing outline of hinge and umbones. 



" 3. ARCA EQTJICOSTATA. Exterior of left valve, and hinge and teeth of right valve. 



Page 44. 



" 4. End view, showing outline hinge and umbones. 



« 5. ARCA LWCOM3RUA. Exterior of left valve, and hinge and teeth of right valve. Page 45. 



" 6. End view, showing outline, hinge and umbones. 



" 7. ARCA PEXATA. Exterior of left valve, and hinge and teeth of right valve. Page 46. 



" 8. End view, showing hinge and umbones. 



