TEREDO. SHIP- IF OEM. 1S£ 
ter, of a silvery white color, and embossed with numerous 
pearly white tubercles : the lower half of these quills is 
clothed with numerous tufts of yellowish lanceolate fringe- 
lice filaments, pointing forwards and disposed in a verticil- 
late or whirled manner, the lateral ones being elongated 
isd themselves fringed on the inside, giving* this part a 
Ira’Jtiful pennated appearance. These feathered append¬ 
ices can be ejected and retracted at pleasure, and are prc- 
:..My instruments of absorption, as the animal is furnished 
xiih a single terminal tube, whose office may perhaps be 
! : :edischarge and deposit of its eggs or spat. 
lathe summer of 1817, ft large piece of fir timber was 
Hied into the mouth of the river Ex, in Devonshire, co¬ 
vered on the outside with the Lepas anatifera, and perfo¬ 
rated with these interesting animals in a living state. They 
tppear to resemble the species which Lamarck observed in 
museum of Cuvier, at Paris, except that he describes 
.e pennated appendages as being jointed : size of the 
last. v. v. 
3. Teredo dorsalis. Back-valued Ship-worm. 
Shell yellowish-white, with often a purplish cast about 
binge, covered with a blackish skin, with a triangular 
pmjection as in the two last, but the narrow space beneath 
j uore strongly and remotely striate in an oblique direc- 
' n, under which is a longitudinal groove bounded by a 
led rib: the side opposite the triangular projection is 
rended and tumid ; in consequence the front margin is 
pointed but well rounded, without the ear-shaped ap- 
jendage : on the back are two additional oblong transverse 
:.rred accessorial valves, one attached to each of the pri- 
-yy valves, and meeting together at the hinge : inside 
'-'.te, glossy, with a strong longitudinal raised rounded 
ty extending from the insertion of the primary tooth to 
'.emargin, the end of which is thickened by a transverse 
but not ending in a knob: hinge with the primary teeth 
;• in the others, and a single supplemental tooth in each 
-ve seated on the hinge, one of which is tubercular, the 
other a small reflected point: the tube is rather rugged, 
cark brown, abrupt and rounded at the lower end, where 
U;e are two large circular orifices. 
The 
