THE MOLLUSCA 965 



The card catalogue is convenient in a small collection. It be- 

 comes absolutely necessary in a large one. The cards should be 

 of uniform size for convenience in handling. If it is desired to 

 have a card for every entry, they can be smaller than if it is desir- 

 able for economy of space to have as many entries as possible on 

 one card. In the latter case a convenient size is that of the ordinary 

 library card, which can be ruled to hold twenty entries. The name 

 of the species is written on the top, and the number of each entry 

 of that species and the locality are entered below. Such a card as 

 this enables the collector to see at a glance not only whether any 

 given species is represented in his collection, but also from what 

 localities, and saves a large amount of time which would otherwise 

 be spent in turning over the leaves of a serial catalogue. The 

 cards can be kept in drawers or boxes of proper size and can be 

 arranged alphabetically under the different genera and families. 

 Guide cards slightly higher than the ordinary card, indicating the 

 genera, can be inserted in their proper places. 



In collections intended for public exhibition, it is usually neces- 

 sary to have the specimens mounted on cards or blocks. But in 

 private collections such an arrangement is a mistake, not only 

 on account of the greater room required for the collection, but 

 particularly because it prevents the handling of the specimens for 

 purposes of study. 



Specimens under an inch in diameter are most conveniently 

 kept in glass vials. These can be obtained from any wholesale 

 druggist. They should be without a neck and of standard sizes. 

 The length will depend upon the standard size of the tray adopted. 

 For my own collection I use three sizes, J, J, f inch in diameter. 

 As these vials are rather fragile, the pressure of the cork is apt to 

 break them. The cork should therefore be softened by rolling or 

 crushing. A pair of plumber's burner pliers is useful for this 

 purpose. The serial number should be put on the cork or on a 

 small piece of paper inside. Specimens too large for the vials 

 should have the number on the shell in ink. Then, if a drawer 

 happens to be overturned, the specimens can be sorted out again 

 without difficulty. 



When numbered, the vials and specimens should be placed in 



