CARD CATALOGUES AND THEIR APPLICATIONS. 105 
Example 8 :— 
umbratica 
Clerck. 
Blackwall, ’61-64, p. 333. 
Epeira. ay % 
The generic name is written at the bottom of the card, to 
enable it to be easily replaced if it should become separated 
from the others. It is not needed when the card is i situ 
in the catalogue. 
The genus card may with advantage be fairly stout, 
but the species cards may be much thinner than those 
usually employed as guides in card catalogues so as to save 
space. 
Every member who is willing to co-operate in collecting 
materials should be provided with a supply of slips of 
manila paper, cut to the same size as the cards and per- 
forated like them. 
On these he may make notes as to characters, occurrence, 
and habits, or references to literature, regarding any species 
he may come across. Care must be taken to use a separate 
slip for each species and to place the name of it at the foot 
of the card. References to literature are very compactly 
and conveniently made by giving in heavy type or under- 
lined the last two figures of the date and the page referred 
to; or, if the publication is one referred to in Dr Field’s 
vatalogue, the year and the class number. Further particulars 
regarding the former mode of reference are given by Prof. 
K. L. Mark (Science, vol. xiii. pp. 31, 32, 1901), and by Dr 
H. H Field (Bull. Soc. Zool. France, vol. xix. pp. 44-47, 1894). 
