Date Shell.
Generic Character.
Testa ovata. Spira brevissima aut nulla. Labium exterius crassissimum, margine interiore crenato. Columella plicata. Basis subintegra. Animal capitatum, capitis fronte profundè emarginato; oculis ad tentaculorum 2 subulatorum basin externam adsitis; tubâ jugulari simplici; pede magno, foliaceo, ponè attenuato; penulâ dilatatâ, testæ latera obtegente.
Typ. Gen. Volutæ perspicula, glabella, prunum, &c. Lin.
Shell oval. Spire very short or concealed. Exterior lip very thick, with the internal margin crenated. Pillar plaited. Base nearly entire. Animal capitate; head notched in front, with lengthened, pointed tentacula, at the external base of which are the eyes; neck with a simple tube; foot large, foliaceous, pointed behind; mantle dilated, and folded over the sides of the shell.
Generic Types Vol. perspicula, glabella, prunum, &c. Lin.
Lamarck first separated the shells comprised in this genus from the Volutes of Linnæus; their principal distinction rests in the formation of the outer lip, which has a very thick margin, more or less toothed on the inner rim; the base likewise is nearly entire, and the inner lip quite wanting.
By these peculiarities, the Date Shells are easily known from the Volutes on the one hand, and the Cowries on the other; and the invaluable researches of M. Adanson, who has described and figured the animals of each of these genera, has established this distinction on the most solid principles; it will, however, be interesting to trace, by the shells only, how beautifully this arrangement is developed.