The European Pile worm, a Dangerous Marine Borer 11 



borers. Luckily for us the great majority of marine borers die be- 

 fore spring of each year, so that only a few live over to propagate the 

 species. 



Teredo navalis in Barnegat Bay 



During the course of oyster investigations carried on in Barnegat 

 Bay last summer, the writer came accidentallv upon a heavy invasion 

 of Teredo navalis. On July 3 a platform of cypress shingling lath, 

 3 by 6 feet, was covered with clean oyster shells and sunk on the 

 northwest line of the Sloop Creek natural bed, some 2 1 /, miles south- 

 east of Barnegat Pier. The platform stood on legs which raised it 



Fig. 8. 



Cypress Platform Which Collapsed in Less Than Six Weeks 

 After it Was Put Overboard in Barnegat Bay 



about 8 inches off the bottom in 6 feet of water. On July 25 the 

 platform was raised and taken into the tidal creek south of Potter's 

 Creek, Bayville, N. J. Here it remained suspended from the labora- 

 tory houseboat, just beneath the surface of the water, until August 

 15, when it collapsed. Upon examination it was found to have been 

 completely riddled by Teredo navalis (fig. 6 and 8). The pileworms, 

 which averaged about 3/5 inch in length, were so closely crowded to- 

 gether that a single piece of lath, 1 by 2 inches, in a swath 2/5 inch 

 wide around the lath showed 77 pairs of protruding pallets. The ma- 

 jority contained larvae ready to throw out. Teredo navalis becomes 

 full grown by autumn of the season in which it attaches to the wood, 

 reaching a length of about 8 inches. Of the native species, Bankia 



