The Conchologist's First Book / A System of Testaceous Malacology, Arranged Expressly for the Use of Schools, in Which the Animals, According to Cuvier, Are Given With the Shells, a Great Number of New Species Added, and the Whole Brought Up, as Accurately as Possible, to the Present Condition of the Science.

by Edgar Allan Poe; Thomas Brown

Recurved Teeth, are those which are bent backwards, as in the hinge of the Panopea and Spondylus.

Middle Teeth, Plate [IV]. fig. 4, d d. These are also termed Cardinal Teeth.

Numerous Teeth, are those small upright teeth, set in rows, of which the hinges of all the species of the genus Arca are formed. Plate [IV]. fig. 10, k k.

Cavity of the Hinge. The hollow depression in which the ligament of the Ostrea is situated, generally of a triangular form. Plate [IV]. fig. 11, g.

Ligament of the Hinge, or cartilage, is that flexible fibrous substance by which the valves are united, and the hinges kept in their proper places; generally situated under the beaks of the shell. Plate [II]. fig. 1, 3, and 4, l l l; Plate [IV]. fig. 3, n.

Beak is the extreme point of the summit of bivalves, which in many species turns spirally downwards or to the one side, as in some species of Venus, &c. From this circumstance it is seldom the highest part of the shell. Plate [II]. fig. 5, r r.

Seam. When the valves are closed, the line of separation between them is so called. Plate [II]. fig. 6, t t.

Umbo. That part situated immediately under the beak. Plate [I]. fig. 6, w; and Plate [II]. fig. 4, w.

Ears. The processes on each side of the beak, in most species of that division of Ostrea, called Pecten; some have one ear very large, and the other small; and some are scarcely observable on one side. Pl. [II]. fig. 2, h h.

Superior Ear. Plate [IV]. fig. 11, h.