TrBIVALVES. 301 



Ex. Truncatella truncatulina, Lowe, Zool. Journ. t. 5. p. 80. 

 Our Plate xxv. fig. 520, 521. It is found on tlie shores of 

 Britain, the Mediterranean, and West Indies. 



TUBA. Lea. A genus of small fossQ shells, described as resem- 

 bling Turbo, but with the aperture more like that of Melania. 

 Lea. Contrib. Geol. PL xvi. fig. 369. 



TUBERCLE, (tuberculus.) A small swelling excrescence, or 

 knob. 



TUBERCULATED. Having a number of small lumps or pim- 

 ples, as Turrilites, fig. 483. 



TUBICINELLA. Lam. {Tubicen, a trumpeter.) Order, Sessile 

 Cirripedes, Lam. — Descr. A cylindrical tube, composed of six 

 elongated valves jointed together side by side, striated, longitu- 

 dinally, surrounded by concentric rings ; aperture circular, en- 

 closed by an opercidum of four valves, placed perpendicularly in 

 an epiphragm. — Obs. The Tubicinellae are found with nearly 

 the whole shell buried in the thick skin of the whale. T. 

 Balsenarum. PL i. fig. 14. 



TUBICOLAEIA. Lam. (Tuba, a. tuhe ; eo?a, an inhabitant.) A 

 family of the order Conchifera Dimyaria, Lam. consisting of 

 bivalves soldered as it were within, or connected with, a testa- 

 ceous tube. The genera contained in this family may be thus 

 distinguished. 



1. AsPEEGiLi/TJM. Valves fixed, tube perforated and fringed. 



Pig. 44. 



2. Tebedina. Valves fixed, prominent, tube closed at one end. 



Possil. Fig. 46, 47. 



3. Clava&ella. One valve fixed, the other free. Pig. 45. 



4. Teeedo. Both valves free, tube open at both ends. Pig. 



48, 49. 



5. PisTULAiirA. Valves free, tube closed at one end, staaight, 



long. Pig. 53, 54. 



6. GrASTEOCH^NA. Valves free, tube closed at one end, short, 



bulbous. Pig. 52. 

 TUBIVALVES. Bl. Shells composed of two valves connected 

 in a tube, corresponding with the family Tubicolse of Lamarck. 



