140 CONCHYLIA— l>/ri/Fl?.4. 36. 



turned towards the hinder side, giving the shell a somewhat 

 heart-shaped appearance, with generally a heart-shaped im- 

 pression under the curvature of the beaks ; and the ligament 

 is almost uniformly placed in the excavated slope of the anterior 

 or opposite side. 



And that the specific characters of this still multitudinous 

 family may be more clearly contrasted and understood, attention 

 to the following definitions will afford much facility and prevent 

 misconception: cancellate, when longitudinal lines or striae are 

 placed in the interstices of the transverse ones, but do not pass 

 over or cut through them : reticulate, when longitudinal lines 

 pass over transverse ones, but do not cut through them : decus- 

 sate, when longitudinal lines cut through the transverse ones. 



The heart-shaped depression under the curvature of the beaks 

 is denominated the areola : and the excavated slope on the oppo- 

 site or anterior side, in which the cartilage is deposited, is calle 

 the area ; the two sides of which are the lips. 



^? Margine interna crenulato. 1-12, 

 With the inner margin notched. 

 -p orbiculo-cordatiB. 

 orbicular heart-shaped. 



verrucosa. Venus testd glohoso-cordatd, laminis transversis nndulatis, 

 lateribus verrucosis, areola cordatd. 

 Shell globular heart-shaped, with transverse jagged plates, warty 



at the sides, and the areola heart'shaped. 

 Venus verrucosa. Linn. Syst. Nat. p. 1130. 

 Gmelin, Syst. p. 3269. 



