107 
ADVANTAGES OF THE SYSTEM. 
Some advantages of a system of this kind may be mentioned as 
follows : 
The check lists and monographs of the different orders are indexes to 
all determined material in the collections, and to all notes, records, and 
important literature pertaining thereto. They also show at once the 
number of species represented in the collection in any given order, 
family, or genus. 
The accessions catalogue contains all original entries referring to all 
the determined as well as undetermined material. 
The species catalogue may not only be an authentic catalogue of all the 
determined species in the collection, but, immediately succeeding the 
the name of each species, may contain reference to, or full notes of, all 
original observations, experiments, etc., together with references to 
available or desirable literature. 
If at any time it is found that a species has been incorrectly deter- 
mined, we have only to make the correction on the species card and 
change the check-list number or name on the record card and transfer 
the set to their proper places, leaving a card in the old position bear- 
ing a reference to the correction. 
By means of the accessions numbers, check-list numbers and cross 
references all available information regarding any determined or un- 
determined species or specimens in the collection may be conveniently 
and quickly traced, either from the specimens to the notes or from 
notes to specimens. 
In tracing from the specimens to the records the accession number 
on the specimen refers to the note in the accessions catalogue, where 
locality, date, food plant, and all other observations noted at the time 
the specimens were taken, together with subsequent notes and refer- 
ences, are found. If the specimen refers to an identified species the check- 
list number or name is found in the space at the left of the note; if a 
check-list number we are at once referred to the species catalogue, where 
references to records, etc., are found. If there is no check list for the 
order represented, and we find instead of the check-list number the 
name of the species, we turn to the index of the synopsis or monograph 
of the order represented to find the family and genus to which it be- 
longs, after which we can easily find the desired information in the 
species catalogue by means of family and genus labels on projecting 
cards in the file. 
In tracing from the note to the specimen, if relating to an identified 
species, we have only to find its family and generic position in the col- 
lection by reference to the check list or synopsis as we have just indi- 
cated. If referring to an undetermined species the specimens are 
found by means of the food- substance label under which the numbered 
specimens are arranged in consecutive order. 
