Lamarck’s Genera of Shells. 81 
Type. Fistulana Clava*. 
Sheath taper, club-shaped, straight; valves of the shell 
elongated, rather arched at the extremities. Indian Seas. 6 Spe- 
cies. Pl. iii. Fig. 20. 
4. Septariat. 
Animal...... 
Tube testaceous, very long, gradually attenuated towards the 
fore part, divided internally by arched partitions, generally 
incomplete. Anterior extremity of the tube, terminated by two 
other slender tubes, not divided internally. 
The septaria are little more than very large fistulana, and 
scarcely deserve to be made into a separate genus. 
Type. Septaria Arenariat. (Serpula polythalamia. Linn.) Indian 
Seas. PI. iii. Fig. 21. 
5. Teredina §. 
Sheath testaceous, tubular, cylindrical, closed at the posterior 
extremity, shewing the two valves of the shell; open at the 
fore part. 
Type. Teredina personata||. 
Tube straight, taper, club-shaped, club by its sinuses, and 
small lobes resembling a larva. Courtagnon. Pl. iii. Fig. 22. 
2 Species, both fossil. 
6. Teredo {. 
Animal very long, vermiform, covered with a testaceous tube, 
anteriorly protruding two short tubes, with two operculiferous 
bodies adhering to their sides, and, posteriorly, a short muscle, 
received ina bivalve shell, to which it is attached. It bores 
wood. 
Tube testaceous, cylindrical, tortuous, open at both ends, 
not belonging to the shell, and covering the animal. Shell 
bivalve, situated posteriorly on the outside of the tube. Valves 
almost lozenge-shaped, concave. 
The teredines do great mischief to ships, by boring their 
planks, &c. 
* Club, + From septum, a division. t Of the sands. 
§ From teredo, as resembling it. || Masked. 
{ vtendov, a worm that bores wood. 
