6 PAPEKS ON C0CCIDJ3 OR SCALE INSECTS. 



can be filed exactly as an index card. The cabinet follows the general 

 plan of a library card index, is of fiye drawers of three partitions 

 each, and holds upward of 2,000 slides. Guide cards were devised to 

 correspond with the slide envelope, and have on their lower edge an 

 extended lip perforated for the countersunk retaining rod which 

 runs just below the level of the slides. This rod holds the guide cards 

 and gives additional security to the slides, which remain steadily in 

 l^lace by their own weight. Each cabinet is arranged with a lock 

 which fastens all five drawers. The latter have the retaining device 

 so that there is no danger of pulling them entirely out and spilling 

 their contents. The envelopes, however, give such protection to the 

 slides that the latter will not break even from falling some distance, 

 and, furthermore, they protect the slides entirely from dust. The 

 slide cabinets, envelopes, and guide cards are all made by the Library 

 Bureau at very reasonable cost. The slide jackets cost about $2 a 

 thousand, and the cabinets are but little more expensive than the ordi- 

 nary index case. 



This system of storing slides allows for additions indefinitely in 

 exact classification, with as minute and accurate subdivisions as may 

 be necessary. It has now been in use some five years and has given 

 complete satisfaction. The work of consulting the slides and han- 

 dling the material is reduced at least two-thirds, and consultation is 

 so easy that it increases the usefulness of the slide collection many 

 times. 



The cabinet described here in some detail is suitable for dry balsam 

 mounts, and in the preparation of slides of Coccidse the mount, as 

 soon as prepared, is dried over an alcohol flame for a few seconds, 

 when it can be put at once into the jacket. In any case where the 

 slide can not be thus dried it must be laid in a horizontal position 

 until the balsam has beconie thoroughly hardened. Once thoroughly 

 dried, the intense heat of Washington summers does not result in any 

 softening or attachment of the slide to the inclosing jacket. 



A card catalogue has been made of all the material which has come 

 to the Department, and the accumulated notes have been systemat- 

 ically arranged so that they are available for instant reference. This 

 work has been done whenever time was available, and has often been 

 interrupted for weeks or months together, but has now resulted in 

 the collection, notes, and records being in exceptional order and in 

 shape for study by the specialist with the greatest economy of time, 



RECENT ADDITIONS AND PRESENT STATUS. 



The deposit of the types of Professor Cockerell's new species repre- 

 sent the most important additions since Comstock's time. Following 

 this commendable example, most of the other workers in this group 



