28 HETEROPTERA OF EASTERN NORTH AMERICA. 



will often be found to contain much moisture. It should then 

 be wiped out with dry cotton and new pieces of blotting paper 

 substituted for the moist ones. 



The use of a liquid known as carbon tetrachloride instead of 

 cyanide as the killing agent is recommended by Bueno. It is 

 nonpoisonous, quick and certain of action. Of its use he says : 

 "A wad of absorbent cotton is put at the bottom of the tube or 

 bottle, wet, but not dripping, with the tetrachloride. This is held in 

 place by two or three blotting paper disks, or by one of thin sheet cork. 

 It is well to put in another piece of cork or blotting paper about one- 

 half to three-fourths inch above the charge to form a gas chamber. The 

 upper partition may be held up by a short (% inch) length of glass tub- 

 ing slightly smaller than the inside dimension of the bottle or tube. In 

 hot weather evaporation of the tetrachloride is rapid and it condenses 

 on the sides of the tube, wetting the insects. This gas chamber prevents 

 the sweating and also makes the bottle last longer. Such bottles are 

 ready for use as soon as prepared and will last for quite some time — 

 as much as five or six expeditions. These bottles have many advantages 

 over cyanide. They are clean, absolutely harmless, not unpleasant in 

 odor, easily prepared, full strength until completely exhausted, and from 

 the point of view for their purpose, absolutely quick and efficient. In- 

 sects may be left in over night and will be quite flexible the next day. 

 And finally, small, delicate forms may be put into smaller tubes, and 

 the gas from the tetrachloride tube poured in (it being heavier than air). 

 In this way Mirids and other delicate forms may be kept separate and 

 quite dry. Its perfect harmlessness makes it ideal for the use of students 

 and young collectors. Tetrachloride is cheap and easily obtained. It is 

 not affected by the laws governing the sale of poisons." 



After the day's collecting the specimens should be either 

 mounted or, if away from home, packed for carrying or ship- 

 ment. The larger ones are best transported by placing them 

 between thin layers of felt, or of cotton separated by layers 

 of tissue paper, in small pasteboard boxes, and these then 

 packed firmly in small cigar boxes. If in a moist climate and 

 packed too closely they are apt to mold in a short time. The 

 smaller ones can be transported easily by placing a few speci- 

 mens in Nos. 1 or ordinary gelatine capsules with a small 

 wad of cotton or tissue paper placed above them (not too 

 closely) to hold them firmly in place. The harder bodied forms 

 may also be transported in small vials of alcohol. 



Labelling Specimens. — With each layer of specimens in 

 a box or in each capsule place a label giving the date and place 

 of capture and an accession number referring to a similar num- 

 ber in a notebook. This number in the book should be followed 

 by any special data regarding the occurrence, food plant or 

 other information concerning the specimens which may be of 



