I 



LUTRARIA LINEATA. 



SPECIFIC CHARACTER. 



Posterior margin with a reflected edge and submarginal 

 carinated line. 



SYNONYM. 



LuTRARiA LiNEATA. NoMs. Jouv. Acad. Ncit. Sc. vol. 



iv. p. 310. 

 LuTRARiA PAPYRACEA ? Lam. Anim. sans Vertehr. vol. 



V. p. 470. 



DESCRIPTION. 



Shell transversely suboval, thin, whitish tinged with fer- 

 ruginous : posterior hiatus patulous ; anterior hiatus linear 

 and commencing below the hinge slope : hinge slope with 

 a rectilinear profile, and flattened, oblong, subcordate sur- 

 face : valves unequally wrinkled : posterior margin round- 

 ed, shorter than the opposite margin, with a reflected edge, 

 and submarginal carinated line ; behind the middle of the 

 disk and some distance before the elevated line is a broad 

 vitta of hardly perceptible longitudinal lines : unthin a lit- 

 tle undulated, posterior margin glabrous, with an obtusely 

 indented, submarginal liii^e, corresponding with the exteri- 

 or carinated one. 



PliATE IX. 



