Plate XI. 



OUTLINES OF ORGANISMS CONSTITUTING FOOD OF MATAGORDA BAY OYSTERS. 



Magnification 1,000. 



1. Coscinodiscus lineatus. 



2. Coscinodiscus excentricus. 



3. Melosira distans. 



4. Navicula didvma. 



5. Synedra sp. 



6. Navicula elliptica. 



7. Synedra commutata. 



8. Prorocentrum micans. 



