146 DIMYAIRA. 



Genus C9. — TEREDO.— Z.?kw«'ws. 



Generic Character. — Animal elongated, worm-shaped, invest- 

 ed in a testaceous tube, boring into wood ; with two anterior, 

 projectile, short tubes, and two opercular processes, adhering to 

 the sides of the tubes ; with a posterior short muscle, pro- 

 tected by a bivalve shell — Tube testaceous, cylindrical, and tor- 

 tuous, pervious at both extremities, and covering the animal. — 

 Shell bivalve, placed externally, and outside the tube ; each pro- 

 vided with a subulate piece within. 



Teredo navalis. — The Ship Teredo, or Ship-worm. Plate 

 XVIII. fig. 18. to 22. Cylindrical, taper, smooth, white, 

 somewhat flexuous, finely striated longitudinally. Inhabits the 

 European seas, in timber. 



Genus 70.— TEREDIN A. — Lanwrc/i. 



Generic Character. — Tube testaceous, tubular, cylindrical, 

 closed at the posterior extremity, but exhibiting the two valves 

 of the shell j anterior extremity open. 



Teredina personata. — The Masqued Teredina. Plate 

 XVIII. fig. 22. Shell consisting of a straight tube, like the 

 stump of a tree, with a club-shaped termination, the club con- 

 sisting of several similar shaped lobes. Fossil from Courtag- 

 non. 



Genus 71.— SEFTARIA.^ Lamarck. 



Generic Character.— With a very long testaceous tube, gra- 

 dually attenuated anteriorly, and appearing as if divided interi- 

 orly by vaulted unfinished partitions ; anterior end of the tube 

 terminated by two other slender tubes, which are not divided. 



There can be no doubt but that the sheath incloses a bivalve, but as no 

 perfect specimen has hitherto been found, the fact has not been authenti- 

 cated. 



Septaria arenaria. — The Sand Septaria. Plate XVIII. 

 fig. 23. Tubular, tapering, terminating in a slender undivided 

 tube. Found in sand on the shores of the Indian sea. 



