Deraeocor's (Heteroptera, Miridae) 87 



Antenna: Lcngtli of the first segment is taken from the point of 

 •greatest constriction just above the basal knob, to the apex; the 

 length of all the segments is taken when each' is horizontal and ex- 

 tended straight to its full length. 



Pronotum : Length is the greatest measurement that can be ob- 

 tained along the median line, between the front margin of the collar 

 and the hind margin of the disk, taken when the disk is turned as 

 nearly horizontal as possible; icidtli at base is taken across the basal 

 angles of the disk; zvidtJi at anterior angles is taken at the point where 

 the front margins of the disk turn sharply inward to the constriction; 

 li^'idtli of eollar is measured when viewed from the dorsal aspect. 



The male genital claspers are shown in the present paper to be 

 excellent characters for separating the species of Deraeocoris. Fot 

 purposes of study and in order to make drawings of the genital clasp- 

 ers, the specimens should be placed in a moist chamber for a few 

 hours. A\'hen sufficiently soft the tip of the abdomen may be picked 

 off with the aid of two needles sharpened like chisels, working be- 

 neath the binocular nficroscope. The claspers may then be carefully 

 separated from the attaching muscles and mounted for study. To make 

 drawings the claspers should be removed to a dish coated with a mix- 

 ture of paraflin and beeswax. This material makes an excellent sur- 

 face for the manipulation of the claspers and for holding them in any 

 desired position. The depth of the dish should be about one inch in 

 order to guard against the claspers springing out when accidentally 

 stressed by the point of the manipulating needle. Later the claspers 

 may be removed on the point of a needle and attached with glue to 

 a triangle mounted on the pin beneath the insect. At any future time 

 the claspers may be studied as mounted on the pin, but if a change in 

 position is required the claspers may easily be removed by placing the 

 point in a watch glass containing water, and when the glue is dis- 

 solved remove to the parafiin dish as before. 



The genital claspers figured in the present paper are all drawn 

 to the same scale and turned to the same relative position for purposes 

 of comparison. The figures were made by working with an eyepiece 

 micrometer in the binocular microscope, a method by measurement 

 which has proved more satisfactory than using the camera lucida. 



The use of an eyepiece micrometer in the binocular microscope 

 is a most valuable asset to the systematic worker, for by means of it 

 a comparison between variovis parts of the insect may be made with 

 the greatest speed and accuracy. For purposes of description the 

 writer has found it a great saving of time to have worked out on a 



