TAB. I. 



Fig. 



1. Ostrea Princeps, page 17. 



a. inside view of lower valve. 



b. outside ditto of upper valve. 



2. Anomia aculeata, p. 9. 



a. outside view of upper valve. 



b. ditto ditto var. striolata. 



3. Anomia ephippium, p. 8. 



a. upper valve of a specimen of var. squamula, showing the radiating costae 



produced by the animal adhering to the umbonal region of a Pecten. 



b. id., specimen formed on the central portion of a Pecten. 



c. id., outside view of var. cylindrica. 



d. the testaceous plug, or lapideous portion of the adductor muscle, commonly 



called the operculum. 



4. Anomia patelliformis, p. 10. 



a. outside of upper valve. 



b. ditto ditto var. undulata. 



The lines indicate the size of the specimens. 



