192 CONCHYLI A— D/THYiJJ. 41. 



been long exposed to the sun and air, bleached to an ivory white- 

 ness, considerably thickened, deeply and beautifully reticulate in 

 long sq^uares, where the interstices or softer parts appear to have 

 been decomposed, and absorbed into the lines of reticulation or 

 harder parts. 



The exposed bones of animals undergo a process similar to this : 

 and the antiquary well knows, that in ancient sculpture on certain 

 stones, probably modifications of lime, the engraved or indented 

 parts gradually fill up, and at length become level with, or even 

 raised above the surrounding surface. 



sen-atum. Cardium testd obovatd nitidd sulphured glaberrimd. 



'^' Shell oboval glossy and sulphur yellow, with the ribs quite obliter- 

 ated. 



Tab. nost. 13, fig. 5. 

 Cardium serratum. Linn. Syst. Nat. p. 1123. 

 Gmelin, Syst. p. 3251. 

 Turton, Linn. Syst. iv. p. 204. 

 Dillwyn, Descript. Catal. p. 124. 

 Cardium citrinum. Wood, Conch, p. 223, tab. 54. fig. 3. 

 Chemnits, vi. p. 193, tab. 18, fig. 189. 

 Pectunculus Isevis. Lister, Conch, tab. 249, fig. 83. 

 Mus. nost. Dredged on the western coasts. 



Shell nearly an inch and a half long, and an inch and a quarter 

 broad, very nearly allied to the last, of which it may possibly be only 

 a variety,* but is of an uniform rich sulphur yellow, with occasion- 

 ally an orange stain about the anterior margin ; the inside strongly 



