THE 



SPECIES OF SHELLS, 



TESTACEOUS MOLLUSCA. 



CLASS CONCHIFERA. 



Animal soft, without articulations, destitute of head or organs of 

 vision, always fixed within a bivalve shell, having external 

 branchiae, a simple circulation and a unilocular heart. 



ORDER DIMYARIA. 



Shell having two separate lateral muscular impressions. 



Section Crassipedes. 



The mantle closed in front, or partly so ; foot thick, posterior ; 

 shell gaping when closed. 



Tribe Tubicola. 



Shell either contained in a testaceous sheath distinct from its 

 valves, or incrusted wholly or partly in the wall of this tube, or 

 projecting outwards. 



ASPERGILLUM. 



Sheath tubular, testaceous, attenuated towards the anterior termi- 

 nation, where it is open, and thickened posteriorly into a club, 

 where the valves of the shell are incrusted on its walls ; club con- 

 vex, with a terminal disk, perforated with scattered, somewhat 

 tubular punctures, having a fissure in the centre. 



A. Javanum. Lam. 1. — Serpula Penis. Lin. 1267. — S. 

 Aquaria. B. p. 1083.— Mar. f. 7.—W. t. 3ft./. 34. Tube white, 

 nearly smooth, being but slightly wrinkled annularly, increasing in 

 size towards the posterior extremity which is terminated by a per- 

 forated disk with a radiated border . . 4. — Indian Ocean. 



A. Vaginiferum. Lam. 2. — Sow. G. f. 1, 2. — Reeve, t. 17. 

 / 1, 2. Tube very long, white, sub-articulated, with foliaceous tubes 

 at the joints ; terminal disk with the radiated border extremely 

 short. — 4, but very much larger tubes have been found. — Red Sea. 



