72 BULLETIN BROOKLYN ENTOM. SOC. VOL. Vil. September 1884 ] 
thoroughly studied, but it of course involves the destruction of a speci- 
men. In practice. and after the student is familiar with the typical form 
of venation, only a limited portion of the wing need be examined, and 
this can be done by carefully denuding of scales, so much of the under- 
side, as is necessary to expose the venation which is to be examined. 
The denuding can be done with a fine sable or camels hair brush, and 
the wing being sustained by the thumbnail of the left hand, will still re- 
main perfect on the upper side. : 
Various methods of nomenclature have been in use to designate the 
nerves or veins: they have been divided into nervures and nervules, veins, 
venules and veinlets, and special names have been given to each branch. 
The simplest method is that adopted by the German entomologists of 
merely numbering the veins, and this method I use in this paper, giving 
a number to each vein that reaches the costal or outer margin, number 
one being the vein reaching the margin nearest to the anal angle. 
Normally the primaries have 12, the secondaries 8 veins, though the 
internal veins whether one or two in number count only as one, for 
reasons hereafter explained; there may be and usually are 9 veins though 
counting as but 8. The costal margin of primaries is usually thickened 
to the apex, and forms the costa. or costal vein of some authors which 
bears no number. From the base to the costal margin beyond the 
middle, runs vein 12 of the numeral system and this is the vena costals 
of Herrich-Schaffer. Below the costal, also from the base runs the dis- 
cal vein (subcostal of H.S.), which gives out mediately or immediately 
six branches. The first and second of these, No. 11 and 10 in the 
numeral system, to the costa, before the apex; No. 9 may arise out of 
10, or out of the main stem. No. 8 usually runs to the apex, and is 
generally one tine ofa fork out of the main stem. No. 7 is variable, 
but usually from the main stem, while No. 6 isnormally from the ex- 
treme end of the discal vein when there is no accessory cell; or, if there 
is one, then from the middle of the lower margin of that cell. The ac- 
cessory cell, is a small usually diamond shaped cell at the upper outer 
angle of the discal cell, and is formed generally by the junction of veins 
8 and g near their inception, though this origin may be and indeed 
generally is confused and not readily traceable. The cell itself when 
present, is easily seen. These veins 6—11 form the discal or subcostal 
system. From the base, running through and rather beyond the middle 
of the wing, is the median vein which gives out four branches, all of 
which run to the outer margin. Ofthese, the lower, No. 2, or sub- 
