68 MISC. PUBLICATION 657, U. S. DEPT. OF AGRICULTURE 
FIGURE 6.—Wood damaged by marine borers: A, Work of the miraflora shipworm 
Teredo miraflora, in cross section; B, work of a gribble, Sphaeroma sp. 
Their distribution is believed to be limited to the shores of the Gulf 
of Mexico. 
THE WOOD LICE 
The crustacean borers are quite distinct from the molluscs in general 
structure, appearance, and method of attacking and destroying marine 
timbers. Both young and old burrow into the surface wood of timbers, 
but are never imprisoned for life within the wood, as are the molluscs. 
Their attacks are confined mostly between low- and half-tide levels, 
where the wood becomes eroded by water and debris coming against 
it, giving that portion of the piling an hourglass shape. 
The crustaceans are also represented by three genera, which are 
found along the Atlantic coast. They are Limnoria and Sphaeroma, 
often called eribbles, or “wood lice” (fig. 6, B), because they are related 
to and closely resemble the sowbugs, and ‘Che/ura, which belongs to 
the group containing the “sand fleas.” 
