April, '11] TOWNSEND: RECORD SYSTEM 251 



Under the present system, as soon as species are identified, the 

 slips belonging to them may be arranged under generic heads in ali)ha- 

 betic order, thus transferring the same slips from the original plant and 

 other head system of the first index to a second index system using 

 the generic names of the insects. At the same time the names of the 

 insects are entered under the original plant and other heads, and the 

 first index is thus retained as a cross-reference catalog to the food-plants 

 and habits. 



It will be seen that when a species has two or more host 

 plants or host insects it will receive as many numbers under the 

 respective heads. Also species associated with one being specially 

 investigated for purpose of bringing together at a glance the parasites 

 available for the latter will take further numbers in consequence. 

 This may be thought a serious objection, and on this account I at 

 first had some misgiving as to the system, but it has not proved so 

 in practise. It makes no difference finally how many numbers a 

 species may have, since each number must necessarily refer at once to 

 the species; on the other hand, it would cause great confusion if two 

 or more species were to appear under the same number. Upon the 

 identification of a species, all the slips, under whatever numbers, come 

 together under its name in the second index, and at the same time the 

 records are left for cross-reference in the first index. The first is a 

 number index, relating to food-plants and habits; the second is a 

 name index, relating to genera and species. The first index system, 

 with names incorporated, will be found of immense practical advan- 

 tage as a supplement to the second index system. 



While this scheme has been devised to meet the wants of an isolated 

 region where entomological work is being inaugurated practically for 

 the first time, it will be quite readily applicable to general economic 

 work at any stage of records. Such species of insects as have been 

 determined will appear in the second index while all notes on species 

 still unnamed may be renumbered and arranged, with new slips of 

 those determined under the first system which is thus elaborated into 

 a food-plant and food-habit index. Such renumbering should prefix 

 some character to the above numbers, as N (meaning new number), 

 or an asterisk or Greek letter, or the number may be written in red 

 ink or otherwise distinguished until the old numbers have been exceed- 

 ed. The new numbers can be added to the specimens without remov- 

 ing the former numbers. For the second system a generic index is 

 found in the head cards alphabetically arranged. The beauty of the 

 whole scheme is that it is capable of immediate application, without 

 the necessity for the names of the insects being predetermined, and of 

 systematic and unlimited extension on the same lines as begun, the 



