PULLA&TRA. 



and we now intend to confine our remarks more par- 

 ticularly to a small part of it, which has not yet been 

 separated from it, except by Bruguiere of whose Capsa 

 the Genus we are now about to treat of forms a 

 part. Lamarck has, indeed, constituted his Venerupis 

 of a part of our Genus, but tbe greater number of its 

 species are by him still left in Venus, The difficulty 

 of ascertaining any distinguishing character between 

 the Lamarckian Venerupis and the Veneres, Pullastra, 

 decussata, and others, except in the apparent habits of 

 the animals, has prevented us hitherto from endeavour- 

 ing to clear up a point to which our attention has fre- 

 quently been directed, but which we now think we have 

 overcome. It is well known that Venus perforans, Mont, 

 Venerupis perforans. Lam. and some of its congeners 

 live in cavities perforated in chalk and limestone rocks, 

 and that the Veneres Pullastra, decussata and several other 

 species that resemble them in general form and appear- 

 ance are found buried in the sand; an apparently well 

 marked difference therefore exists in the habits of their 

 respective animals: we think, however, that we have 

 evidence to prove that there exists in reality very little 

 difference, and that the cavities in which Lamarck's 

 Venerupes live, are rather the natural consequence of the 

 action of the sea water in conjunction with some of the 

 excretions of the animal upon the chalk or limestone, 

 than of any power of the animals themselves to pierce, 

 independently of such action: so that the difference is 

 really only in the nature of the shore on which the very 

 young shells are accidentally deposited, those which 

 are thrown upon a sandy bottom, burying themselves in 

 the sand, and such as are deposited upon limestone or 

 chalk producing a cavity in which they live. 



The shells which we now propose to unite together 

 under one appellation are Lamarck's Venerupes, and the 

 following of his Veneres, viz. V, Malaharica, papilionacea 

 adspersa, punctifera, turgida, litterata^ sulcaria, Textile, 

 texturata, geographica, rariflamma, decussata, Pullastra, 

 aurea, virginea, and some others : and for the Genus thus 

 constituted we propose the name of Pullmtra, rejecting 

 the term Venerupis or Venerirupis, because it would 

 convey the false idea that at least the greater number of 

 the species were inhabitants of rocks. 



