198 UNIVALVES —— TEREDO. 
head of the animal, resembling the Pholas; it also has 
two smaller valves of an ovate form, at the other extremi- 
ty. The destructive effects of this little animal would 
frequently occasion the loss of the largest vessels, were 
it not from the singular fact of their generally perforat- 
ing the wood in the direction of the grain. 
The T. utriculus is also cylindrical, undulated, and 
solid; it is usually about seven inches in length, and 
found in wood that has lain some time under water. It 
is white, subpellucid, very much bent, and gradually 
tapering; the aperture is ovate, divided in the middle 
by a partition. 
The last species is the T. clava, which is found in 
the seminal vessels of the Xylocarpus Granatum; one 
end is clavate, the other incurved, narrower, obtuse, and 
perforated in the middle: the shell is generally flex- 
uous, and has a brownish color; the exterior is rough, 
but within it is perfectly smooth. It is nearly two 
inches long, and about half an meh in diameter. 
The generic name Tcondwyv (Teredo) is derived from 
TEoEW, tO bore. 
Scienttfic Name. Locality. Common Name. 
Gigantea --:--- Sumatra, Ceram -:----- Gigantic Teredo 
Navalis --+--+++- Sides & bottoms of Ships Ship ---:-- do -- 
Utriculus ---+--- Wood in the Sea -:-+--- Timber --- do -- 
Clava s+rrseeres Coromandel .---- se +.  Club-shap’d do «- 
