Although the Brachiopoda, or "Lamp-shells," are not true mollusca, they are not very far removed from them, and are so often to be found in cabinets that it will not do to pass them over, especially since in past times they were very abundant, an enormous number occurring in the fossil state. Only eight genera are now living. Shells belonging to this class are readily recognised by the fact of one valve being larger than the other, and possessing a distinct peak, the apex of which is perforated. The Terebratulidæ are the most extensive family of this class.
Fig. 23. Teredo navalis.
HOW TO ARRANGE THE SHELLS IN THE CABINET.
When you have arranged your specimens in the order above indicated, proceed to place them in your boxes, arranging and labelling them after the manner shown in the accompanying diagram.
+----------+----------+----------+----------+----------+
| Class. | | | | |
+----------+ Species. | Species. | Species. | Species. |
| Order. | | | | |
+----------+----------+----------+----------+----------+
| Family | | | | |
| Name. | | | | |
+----------+ Species. | Species. | Species. | Species. |
| Generic | | | | |
| Name. | | +----------+ |
+----------+----------+----------+ Family +----------+
| | | | Name. | |
| Species. | Species. | Species. +----------+ Species. |
| | | | Generic | |
+----------+----------+----------+ Name. +----------+
| | | +----------+ |
| | Generic | | | |
| Species. | Name. | Species. | Species. | Species. |
| | | | | |
+----------+----------+----------+----------+----------+
| | | | | Generic |
| Species. | Species. | Species. | Species. | Name. |
| | | | | |
+----------+----------+----------+----------+----------+
| | | Generic | | |
| Species. | Species. | Name. | Species. | Species. |
| | | | | |
+----------+----------+----------+----------+----------+
| | | | | |
| Species. | Species. | Species. | Species. | Species. |
| | | | | |
+----------+----------+----------+----------+----------+
On the lid, or on a slip of paper or card placed at the head of your columns of trays, write the class and order, with its proper number (I., II., etc., as the case may be); then at the top of your left-hand column place the family and its number, and under it the name of the first genus. The species (one in each tray) come next, then the name of the next genus following it, succeeded by its species, and so on.