228 



Fig. 84 



1. Shell of Teredo navalis mounted in position at end of burrow, dorsal \ icw. x 10. 



2. Shell of Teredo navalis mounted in position at end of burrow, lateral view, x 10. 



3. Cupped extremity of a burrow of Teredo navalis, showing markings made by the shel 



4. Same, smaller specimen. 



10. 



