68 Bulletin 5 338 



Explanation of Plate IX. "" 



( 28 ) 



Page. 



Fig. I. Pecten jeffersonius... 133, 309. 



2. Pecten clintonius ^ 135, 311. 



3. Pecten septenarius ■.. 136, 312. 



4. Plicatula marginata " " 



5. Astarte undulata 150, 326. 



6. Astarte vicina 151, 327. 



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