199 



3. Lingula, — A subequivalved, flat, ovally oblong bi- 

 valve, truncated at its top ; rather pointed at its base ; 

 raised on a fleshy tendinous pedicle, and fixed to marine 

 bodies ; the hinge toothless. Recent and fossil. — PI. vi. 

 fig. 28. 



Cirrhipeda. — Soft animals, without head or eyes, fixed 

 and testaceous. The shell either sessile, or raised on a 

 flexible tendinous pedicle. 



Sessile. — Shell fixed generally on marine bodies ; the 

 mouth in the upper and anterior part. 



1. Tuhicinella. — A straight cylindraceo-tubular opercu- 

 lated shell, attenuated towards its base, girt with transverse 

 annular ribs ; truncated at both ends, shut at the bottom by 

 a membrane, and open at the top. The operculum formed 

 of four small obtuse valves. — Attached to the whale ; but 

 not known in a mineralized state. 



2. Coronula, — A sessile, suborbicular, or subconical shell, 

 the extremities truncated ; the sides thick ; hollowed out 

 internally into radiating cells. The operculum formed by 

 four small obtuse valves. Recent, and very rarely fossil. 

 — PI. viii. fig. 27. — The figure given here is of the fossil 

 coronula of the whale. 



3. Balanus. — A sessile, affixed, conical univalve, the 

 apex truncated ; the base closed by an adherent testaceous 

 plate ; the opening subtrigonal or elliptical ; the operculum 

 internal, with four moveable valves inserted near the inner 

 base of the shell. Recent and fossil. — PL viii. fig. 26. 



4. Acasta. A sessile body, composed of separable 



pieces, with a convex base, and a four-valved operculum. 

 Recent. 



5. Creusia. — Sessile and subglobular, formed of four 

 valves, and having an internal bivalved operculum. Recent. 



6. Pyrgoma, — Sessile, subglobular, with a bivalved oper- 

 culum : found on astrea, madrepora, &c. Recent. 



